diff --git a/accounts/addproofer.php b/accounts/addproofer.php
index 4c999d2c9..0b0ea62c6 100644
--- a/accounts/addproofer.php
+++ b/accounts/addproofer.php
@@ -284,7 +284,7 @@ function _validate_fields(
 
     // Ensure we don't already have a registration with this name
     try {
-        $na_user = new NonactivatedUser($username);
+        new NonactivatedUser($username);
         return _("That username has already been requested. Please try another.");
     } catch (NonexistentNonactivatedUserException$exception) {
         // pass
diff --git a/api/index.php b/api/index.php
index fe9028f78..c8a2d384c 100644
--- a/api/index.php
+++ b/api/index.php
@@ -163,8 +163,8 @@ function api_send_pagination_header(array $query_params, int $total_rows, int $p
         }
 
         if (is_array($value)) {
-            foreach ($value as $subkey => $value) {
-                $params[] = "{$key}[]=" . urlencode($value);
+            foreach ($value as $value_element) {
+                $params[] = "{$key}[]=" . urlencode($value_element);
             }
         } else {
             $params[] = "$key=" . urlencode($value);
diff --git a/api/v1_projects.inc b/api/v1_projects.inc
index 9e70d03ee..70e842b71 100644
--- a/api/v1_projects.inc
+++ b/api/v1_projects.inc
@@ -149,7 +149,6 @@ function api_v1_projects(string $method, array $data, array $query_params): arra
         throw new ServerError(DPDatabase::log_error());
     }
     [$total_rows] = mysqli_fetch_row($result_count);
-    $total_pages = round($total_rows / $per_page);
 
     api_send_pagination_header($query_params, $total_rows, $per_page, $page);
 
@@ -420,7 +419,7 @@ function api_v1_project_artifacts(string $method, array $data): array
 
     $response = [];
     if ($stage->id == "PP") {
-        [$zipfile_path, $zipfile_url] = generate_project_images_zip($project->projectid);
+        [$_zipfile_path, $zipfile_url] = generate_project_images_zip($project->projectid);
 
         $response[] = [
             "stage" => $stage->id,
@@ -838,7 +837,7 @@ function api_v1_projects_specialdays(string $method, array $data, array $query_p
 
     $special_days = load_special_days();
     $enabled_filter = _get_enabled_filter($query_params);
-    foreach ($special_days as $spec_code => $special_day) {
+    foreach ($special_days as $special_day) {
         $enabled = $special_day["enable"] == 1;
         if ($enabled_filter !== null) {
             if ($enabled_filter != $enabled) {
@@ -885,7 +884,7 @@ function api_v1_projects_imagesources(string $method, array $data, array $query_
     $image_sources = load_image_sources();
 
     $enabled_filter = _get_enabled_filter($query_params);
-    foreach ($image_sources as $id => $image_source) {
+    foreach ($image_sources as $image_source) {
         $is_active = $image_source["is_active"] == 1;
         if ($enabled_filter !== null) {
             if ($enabled_filter != $is_active) {
@@ -989,7 +988,7 @@ function api_v1_project_wordcheck(string $method, array $data): array
     }
 
     $text = receive_project_text_from_request_body();
-    [$bad_words, $languages, $messages] = get_bad_word_levels_for_project_text($text, $project->projectid, $languages, $accepted_words);
+    [$bad_words, $_languages, $messages] = get_bad_word_levels_for_project_text($text, $project->projectid, $languages, $accepted_words);
     return [
         "bad_words" => $bad_words,
         "messages" => $messages,
diff --git a/credits.php b/credits.php
index fe460097b..b3171b53f 100644
--- a/credits.php
+++ b/credits.php
@@ -122,7 +122,7 @@ function load_composer_credit_details()
     }
     $packages = json_decode($contents, flags: JSON_THROW_ON_ERROR);
     $credit_details = [];
-    foreach ($packages->packages as $index => $package) {
+    foreach ($packages->packages as $package) {
         $credit_details[$package->name] = new CreditDetails(
             name: $package->name,
             url: $package->homepage ?? null,
diff --git a/crontab/AutoModify.inc b/crontab/AutoModify.inc
index 47ed6bd80..84870db82 100644
--- a/crontab/AutoModify.inc
+++ b/crontab/AutoModify.inc
@@ -22,7 +22,12 @@ class AutoModify extends BackgroundJob
         if (($this->filehandle = fopen($this->logfile, "wt")) === false) {
             throw new RuntimeException(sprintf(_("Failed to open log file %s."), $this->logfile));
         }
-        ob_start([$this, 'flush'], 1024);
+        ob_start(function (string $buffer) {
+            if (!is_null($this->filehandle)) {
+                fwrite($this->filehandle, $buffer);
+            }
+            return $buffer;
+        }, chunk_size: 1024);
 
         automodify();
         autorelease();
@@ -30,12 +35,4 @@ class AutoModify extends BackgroundJob
         ob_end_flush();
         fclose($this->filehandle);
     }
-
-    private function flush(string $buffer, int $phase): string
-    {
-        if (!is_null($this->filehandle)) {
-            fwrite($this->filehandle, $buffer);
-        }
-        return $buffer;
-    }
 }
diff --git a/feeds/backend.php b/feeds/backend.php
index a5c1aac56..7e1620ca2 100644
--- a/feeds/backend.php
+++ b/feeds/backend.php
@@ -95,7 +95,6 @@ function generate_rss_feed(string $content, string $site_name, string $code_url,
         $data = '';
         $result = DPDatabase::query($query);
         while ($row = mysqli_fetch_array($result)) {
-            $posteddate = date("r", ($row['modifieddate']));
             $data .= "<item>
             <title>".xmlencode($row['nameofwork'])." - ".xmlencode($row['authorsname'])."</title>
             <link>".xmlencode("$code_url/project.php?id=".$row['projectid'])."</link>
diff --git a/locale/translators/index.php b/locale/translators/index.php
index 793ecf7ba..3b20bbb90 100644
--- a/locale/translators/index.php
+++ b/locale/translators/index.php
@@ -332,7 +332,6 @@ function main_form(): void
         echo "<li>" . _("Last modified") . ": "
                 . date("F d Y H:i:s", $pot_file->last_modified) . "</li>";
         $total_strings = $pot_file->messages_count;
-        $translated_strings = $pot_file->messages_translated_count;
         echo "<li>" . sprintf(_("%d strings total"), $total_strings) . "</li>";
         echo "</ul></p>";
     } else {
diff --git a/pinc/Activity.inc b/pinc/Activity.inc
index 13975b34d..8071dcfd4 100644
--- a/pinc/Activity.inc
+++ b/pinc/Activity.inc
@@ -269,9 +269,6 @@ class Activity
             }
         }
 
-        $can_access = false;
-        $request_status = null;
-
         if ($recorded_access == 'denied') {
             // they are not allowed to access this activity or to request access
             $can_access = false;
@@ -604,7 +601,7 @@ function show_user_access_chart(?string $username): void
             if (is_null($row)) {
                 echo "<td></td>";
             } else {
-                [$criterion_str, $minimum, $user_score, $satisfied] = $row;
+                [$_criterion_str, $minimum, $_user_score, $satisfied] = $row;
                 td_w_bgcolor($minimum, $satisfied);
             }
         }
diff --git a/pinc/CharSuites.inc b/pinc/CharSuites.inc
index eae5173c0..05e98d0b0 100644
--- a/pinc/CharSuites.inc
+++ b/pinc/CharSuites.inc
@@ -194,7 +194,7 @@ class CharSuites
     public static function enable(string $name): void
     {
         // Validate we have a valid charsuite
-        $charsuite = CharSuites::get($name);
+        CharSuites::get($name);
 
         $sql = sprintf(
             "
diff --git a/pinc/DPage.inc b/pinc/DPage.inc
index 0a53b65a1..0a63e0fd2 100644
--- a/pinc/DPage.inc
+++ b/pinc/DPage.inc
@@ -56,7 +56,7 @@ function project_allow_pages(string $projectid): void
 function project_drop_pages(string $projectid): void
 {
     validate_projectID($projectid);
-    $result = DPDatabase::query("DROP TABLE $projectid");
+    DPDatabase::query("DROP TABLE $projectid");
 
     _project_adjust_n_pages($projectid, 'NONE');
     _project_adjust_n_available_pages($projectid, 'NONE');
@@ -89,7 +89,7 @@ function Pages_prepForRound(string $projectid, int $round_number): void
             SET
                 $setters
         ";
-        $result = DPDatabase::query($sql);
+        DPDatabase::query($sql);
 
         _project_adjust_n_available_pages($projectid, 'ALL');
     }
diff --git a/pinc/MARCRecord.inc b/pinc/MARCRecord.inc
index 0bc792006..874a23f64 100644
--- a/pinc/MARCRecord.inc
+++ b/pinc/MARCRecord.inc
@@ -394,8 +394,6 @@ class MARCRecord
 
     public function get_author(): string
     {
-        $author = "";
-
         $author_fields = [
             "100", // https://www.loc.gov/marc/bibliographic/concise/bd100.html Main Entry--Personal Name
             "700", // https://www.loc.gov/marc/bibliographic/concise/bd700.html Added Entry--Personal Name
@@ -467,7 +465,6 @@ class MARCRecord
 
     public function get_type_of_record(): string
     {
-        $lang_name = "";
         // https://www.loc.gov/marc/bibliographic/bdleader.html Leader
         // Character 6 - Type of record
         $leader = $this->record[0][1]; // The leader is always the first record.
@@ -612,7 +609,7 @@ class MARCRecord
                 $length = sprintf("%04d", $length + 1);
                 $directory .= $length.$start;
 
-                foreach ($this->record as $field => $field_value) {
+                foreach ($this->record as $field_value) {
                     if (preg_match("/^\(3,".substr($tag_value[0], 3, 3)."\)\(3,[012[:space:]]+\)$/", $field_value[0]) && !in_array(substr($tag_value[0], 3, 3), $stack)) {
                         $data .= "\x1E".substr($field_value[0], 10, 2);
                     }
diff --git a/pinc/POFile.inc b/pinc/POFile.inc
index 8db2c1a36..744cda911 100644
--- a/pinc/POFile.inc
+++ b/pinc/POFile.inc
@@ -91,7 +91,7 @@ class POFile
      */
     private function is_block_translated(string $block): bool
     {
-        [$msgid, $msgstr] = @explode("msgstr", $block);
+        [$_msgid, $msgstr] = @explode("msgstr", $block);
         $msgstr = "msgstr$msgstr";
         if (strpos($msgstr, 'msgstr ""') === 0 &&
             substr_count($msgstr, "\n") == 1) {
diff --git a/pinc/Project.inc b/pinc/Project.inc
index 705d089ca..8415af491 100644
--- a/pinc/Project.inc
+++ b/pinc/Project.inc
@@ -1391,7 +1391,7 @@ class Project
                 // $name ($project->scannercredit) could be
                 // a username or just a typed-in string
                 try {
-                    $user = new User($name);
+                    new User($name);
                 } catch (NonexistentUserException $exception) {
                     // $name is not a username.
                     // So use it as the credit.
@@ -1494,7 +1494,7 @@ class Project
             $topic_id,
             DPDatabase::escape($this->projectid)
         );
-        $update_project = DPDatabase::query($sql);
+        DPDatabase::query($sql);
         $this->topic_id = $topic_id;
 
         return $topic_id;
@@ -1508,7 +1508,6 @@ class Project
      */
     public function email_introduction(): string
     {
-        $projectid = $this->projectid;
         $title = $this->nameofwork;
 
         return implode("\n", [
@@ -1915,7 +1914,6 @@ function project_get_auto_PPer(string $projectid): ?string
     $project = new Project($projectid);
     $checkedoutby = $project->checkedoutby;
     $username = $project->username;
-    $possible_PPer = '';
     if ($checkedoutby != '') {
         // The project is reserved for a PPer, so it will be checked out to him/her.
         $possible_PPer = $checkedoutby;
diff --git a/pinc/ProjectSearchForm.inc b/pinc/ProjectSearchForm.inc
index c2ed4ea47..de355cc68 100644
--- a/pinc/ProjectSearchForm.inc
+++ b/pinc/ProjectSearchForm.inc
@@ -250,7 +250,7 @@ class ProjectSearchForm
         }
 
         // then everything else
-        foreach (get_iso_language_list() as $k => $v) {
+        foreach (get_iso_language_list() as $v) {
             if (!isset($lang_options[$v['lang_name']])) {
                 $lang_options[$v['lang_name']] = $v['lang_name'];
             }
diff --git a/pinc/ProjectSearchResults.inc b/pinc/ProjectSearchResults.inc
index 814fbb286..8c7517f50 100644
--- a/pinc/ProjectSearchResults.inc
+++ b/pinc/ProjectSearchResults.inc
@@ -537,8 +537,7 @@ class ProjectSearchResults
     private function get_sort_sql(string $col_id): ?string
     {
         foreach ($this->active_columns as $column) {
-            if ($column->sortable && ($column->id == $col_id)) {
-                $valid = true;
+            if ($column->sortable && $column->id == $col_id) {
                 return $column->get_sort_sql();
             }
         }
diff --git a/pinc/ProjectTransition.inc b/pinc/ProjectTransition.inc
index 6278221f4..c9b6c9571 100644
--- a/pinc/ProjectTransition.inc
+++ b/pinc/ProjectTransition.inc
@@ -267,7 +267,7 @@ class ProjectTransition
             SET $settings
             WHERE projectid = '$escaped_projectid'
         ";
-        $res = DPDatabase::query($sql);
+        DPDatabase::query($sql);
 
         // ---------------------------------------------------------------------
         // Okay, so the update to the 'projects' table succeeded.
diff --git a/pinc/RandomRule.inc b/pinc/RandomRule.inc
index c1b617256..14cc837a4 100644
--- a/pinc/RandomRule.inc
+++ b/pinc/RandomRule.inc
@@ -213,7 +213,7 @@ class RandomRule
             if (preg_match('/^<div id="(.*)"><\/div>$/', $line, $matches)) {
                 if ($in_rule) {
                     RandomRule::_add_rule($document, $langcode, $url, $anchor, $subject, $rule);
-                    $anchor = $subject = $rule = "";
+                    $subject = $rule = "";
                 }
                 $anchor = $matches[1];
                 $in_rule = true;
@@ -223,7 +223,7 @@ class RandomRule
             if (preg_match('/<h3><a name="(.*)">(.*)<\/a><\/h3>/', $line, $matches)) {
                 if ($in_rule) {
                     RandomRule::_add_rule($document, $langcode, $url, $anchor, $subject, $rule);
-                    $anchor = $subject = $rule = "";
+                    $rule = "";
                 }
                 $anchor = $matches[1];
                 $subject = $matches[2];
diff --git a/pinc/TableDocumentation.inc b/pinc/TableDocumentation.inc
index 747d4eb38..2aef6df53 100644
--- a/pinc/TableDocumentation.inc
+++ b/pinc/TableDocumentation.inc
@@ -41,7 +41,7 @@ class TableDocumentation
         $lines = [];
 
         // Add column definitions
-        foreach ($this->columns_information as $index => $column_information) {
+        foreach ($this->columns_information as $column_information) {
             $lines[] = '## `' . $column_information['Field'] . '`';
             $lines[] = '';
         }
@@ -65,7 +65,7 @@ class TableDocumentation
     {
         $column_names = [];
 
-        foreach ($this->columns_information as $index => $column_information) {
+        foreach ($this->columns_information as $column_information) {
             $column_names[] = $column_information['Field'];
         }
 
@@ -140,7 +140,7 @@ class TableDocumentation
         $encountered_columns = [];
         $should_delete_this_part = false;
 
-        foreach ($lines as $index => $line) {
+        foreach ($lines as $line) {
             if (str_starts_with($line, '## `')) {
                 // 01234         10
                 // ## `column_name`
@@ -160,7 +160,7 @@ class TableDocumentation
 
         $missing_column_names = array_diff($column_names, $encountered_columns);
 
-        foreach ($missing_column_names as $index => $column_name) {
+        foreach ($missing_column_names as $column_name) {
             $lines_with_updated_column_definitions[] = "## `$column_name`\n\n";
         }
 
@@ -183,7 +183,7 @@ class TableDocumentation
         $reached_table = false;
         $finished_table = false;
 
-        foreach ($lines as $index => $line) {
+        foreach ($lines as $line) {
             if (str_starts_with($line, '|') && !$finished_table) {
                 $reached_table = true;
             } elseif ($reached_table && !$finished_table) {
@@ -211,7 +211,7 @@ class TableDocumentation
     {
         $first_table_lines = [];
 
-        foreach ($lines as $index => $line) {
+        foreach ($lines as $line) {
             if (str_starts_with($line, '|')) {
                 $first_table_lines[] = $line;
             } elseif (count($first_table_lines) > 0) {
diff --git a/pinc/autorelease.inc b/pinc/autorelease.inc
index 1b2548a2e..5860a3c8b 100644
--- a/pinc/autorelease.inc
+++ b/pinc/autorelease.inc
@@ -215,7 +215,7 @@ function autorelease_for_round(Round $round): void
         echo "    Released <b>{$n_projects->released}</b> {$qd->name} projects.\n";
     }
 
-    AP_teardown($round);
+    AP_teardown();
 
     echo "\n";
     echo "Finished round {$round->id}\n";
@@ -593,7 +593,7 @@ function AP_setup(Round $round): void
     }
 }
 
-function AP_teardown(Round $round): void
+function AP_teardown(): void
 {
     $sql = "DROP TABLE active_page_counts";
     DPDatabase::query($sql);
diff --git a/pinc/bad_bytes.inc b/pinc/bad_bytes.inc
index 771f2ad54..0e55aee3e 100644
--- a/pinc/bad_bytes.inc
+++ b/pinc/bad_bytes.inc
@@ -644,8 +644,6 @@ function define_bad_byte_sequences(): void
     $_bad_byte_sequences = [];
 
     foreach ($_character_data as $code_point => $info) {
-        $char_name = $info['name'];
-
         @$entity_name = $info['e'];
         if ($entity_name) {
             $entity_ref = "&$entity_name;";
diff --git a/pinc/forum_interface_phpbb3.inc b/pinc/forum_interface_phpbb3.inc
index e0c2b6f6b..9ce870973 100644
--- a/pinc/forum_interface_phpbb3.inc
+++ b/pinc/forum_interface_phpbb3.inc
@@ -695,8 +695,6 @@ function get_last_post_time_in_topic(int $topic_id): ?int
  */
 function get_topic_details(int $topic_id): ?array
 {
-    $forums_phpbb_dir = SiteConfig::get()->forums_phpbb_dir;
-
     $phpbb_topics = phpbb_table("topics");
     $phpbb_forums = phpbb_table("forums");
     $phpbb_users = phpbb_table("users");
diff --git a/pinc/gettext_setup.inc b/pinc/gettext_setup.inc
index 2007a3f1a..253509f48 100644
--- a/pinc/gettext_setup.inc
+++ b/pinc/gettext_setup.inc
@@ -61,7 +61,7 @@ function configure_gettext(string $locale): void
     // ignore whatever is here, so unset it
     putenv("LANGUAGE=");
 
-    $locale = setlocale(LC_ALL, $locale);
+    setlocale(LC_ALL, $locale);
 
     // Specify location of translation tables and choose domain
     $gettext_domain = 'messages';
diff --git a/pinc/gradual.inc b/pinc/gradual.inc
index 2e8d0ed61..6ebb4dfb1 100644
--- a/pinc/gradual.inc
+++ b/pinc/gradual.inc
@@ -73,8 +73,7 @@ function welcome_see_beginner_forum(int $pagesproofed, string $page_id, ?string
         echo "<p>";
         echo sprintf(_('Before you can begin proofreading, you must have:'));
         echo "<ul>";
-        foreach ($uao->minima_table as $row) {
-            [$criterion_str, $minimum, $user_score, $satisfied] = $row;
+        foreach ($uao->minima_table as [$criterion_str, $_minimum, $_user_score, $_satisfied]) {
             echo "<li>$criterion_str</li>";
         }
         echo "</ul>\n";
@@ -221,8 +220,7 @@ function maybe_output_new_proofer_project_message(Project $project): void
         echo "<p>";
         echo sprintf(_('Before you can begin proofreading, you must have:'));
         echo "<ul>";
-        foreach ($uao->minima_table as $row) {
-            [$criterion_str, $minimum, $user_score, $satisfied] = $row;
+        foreach ($uao->minima_table as [$criterion_str, $_minimum, $_user_score, $_satisfied]) {
             echo "<li>$criterion_str</li>";
         }
         echo "</ul>\n";
@@ -372,7 +370,7 @@ function encourage_highest_round(?string $username, ?string $round_id = null): v
         // except the quizzes (eg number of days and pages done), nudge them along.
         $ready_ignoring_quizzes = true;
         $quiz_requirements = [];
-        foreach ($uao->minima_table as $criterion_code => [$criterion_str, $minimum, $user_score, $satisfied]) {
+        foreach ($uao->minima_table as $criterion_code => [$_criterion_str, $_minimum, $_user_score, $satisfied]) {
             // skip checking any quiz criteria for pass
             if (str_starts_with($criterion_code, 'quiz/')) {
                 $quiz_requirements[] = $criterion_code;
diff --git a/pinc/graph_data.inc b/pinc/graph_data.inc
index cccc3dc91..493a001fe 100644
--- a/pinc/graph_data.inc
+++ b/pinc/graph_data.inc
@@ -153,8 +153,6 @@ function user_logging_on(string $past, string $preceding): array
   */
 function tallyboard_deltas(string $tally_name, string $holder_type, int $holder_id, string|int $days_back): array
 {
-    $valid_tally_names = array_keys(get_page_tally_names());
-
     $pages_per_day = get_pages_per_day_for_past_n_days($tally_name, $holder_type, $holder_id, $days_back);
 
     $datax = array_keys($pages_per_day);
@@ -732,8 +730,6 @@ function _get_project_state_selector(string $which, array|string|null $desired_s
         $desired_states = [$desired_states];
     }
 
-    $sql = "";
-
     // see if it's a round
     $round = get_Round_for_round_id($which);
     if ($round != null) {
diff --git a/pinc/new_user_mails.inc b/pinc/new_user_mails.inc
index efc707f27..6260216bb 100644
--- a/pinc/new_user_mails.inc
+++ b/pinc/new_user_mails.inc
@@ -53,14 +53,11 @@ function send_welcome_mail(string $email, string $real_name, string $username):
 
     $code_url = SiteConfig::get()->code_url;
     $site_name = SiteConfig::get()->site_name;
-    $site_abbreviation = SiteConfig::get()->site_abbreviation;
     $site_url = SiteConfig::get()->site_url;
     $general_help_email_addr = SiteConfig::get()->general_help_email_addr;
 
     $welcome = "Welcome to the $site_name Site!";
 
-    $reset_password_url = get_reset_password_url();
-
     // SITE-SPECIFIC
     // Much of the contents of the email below is DP site-specific, however
     // not so much that it would be horrible for non-DP sites to use it without
diff --git a/pinc/page_table.inc b/pinc/page_table.inc
index 4f3a6cab6..3ae877bef 100644
--- a/pinc/page_table.inc
+++ b/pinc/page_table.inc
@@ -111,7 +111,7 @@ function fetch_page_table_data(Project $project, $page_selector = null, ?Round $
     if ($round_ids_to_load_wordcheck_events) {
         $sql = sprintf(
             "
-            SELECT image, username, round_id, count(*)
+            SELECT image, username, round_id
             FROM wordcheck_events
             WHERE projectid = '%s' and round_id in (%s)
             GROUP BY image, username, round_id
@@ -122,7 +122,7 @@ function fetch_page_table_data(Project $project, $page_selector = null, ?Round $
         $res = DPDatabase::query($sql);
 
         $wordcheck_events = [];
-        while ([$image, $username, $round_id, $count] = mysqli_fetch_row($res)) {
+        while ([$image, $username, $round_id] = mysqli_fetch_row($res)) {
             $wordcheck_events["$image$username$round_id"] = 1;
         }
     } else {
@@ -181,7 +181,6 @@ function fetch_page_table_data(Project $project, $page_selector = null, ?Round $
                 ON (users$rn.username = $round->user_column_name)
             $joined_with_user_page_tallies
         ";
-        $prev_text_column_name = $round->text_column_name;
     }
 
     if (is_null($page_selector)) {
@@ -205,7 +204,6 @@ function fetch_page_table_data(Project $project, $page_selector = null, ?Round $
                 OR $work_round->user_column_name = '%s'
             ", DPDatabase::escape($username_for_selecting_pages));
         }
-        $page_selector = null;
     } else {
         // $page_selector is an array whose keys are imagenames of the pages to select
         $imagenames_str = surround_and_join(array_keys($page_selector), "'", "'", ",");
@@ -345,7 +343,7 @@ function echo_page_table(
 
         echo "{$td_start}"._("Page State")."{$td_end}";
 
-        foreach ($rounds_to_display as $round) {
+        foreach ($rounds_to_display as $_) {
             echo "{$td_start}"._("Diff")."{$td_end}";
             echo "{$td_start}"._("Date")."{$td_end}";
             echo "{$td_start}"._("User")."{$td_end}";
diff --git a/pinc/page_tally.inc b/pinc/page_tally.inc
index feb56edb3..346ef4730 100644
--- a/pinc/page_tally.inc
+++ b/pinc/page_tally.inc
@@ -519,7 +519,7 @@ function get_site_tally_cumulative_or_incremental(
     // if no data was returned from the SELECT, create an empty dataset
     if (empty($datax)) {
         // set arrays to empty before populating them
-        $datax = $datay1 = [];
+        $datay1 = [];
         $datay2 = null;
 
         // don't go past the current date
diff --git a/pinc/post_files.inc b/pinc/post_files.inc
index e9462942b..e9ccf4361 100644
--- a/pinc/post_files.inc
+++ b/pinc/post_files.inc
@@ -154,7 +154,7 @@ function get_page_texts(mysqli_result $pages_res): array
 {
     $page_texts = [];
     while (($row = page_info_fetch($pages_res)) !== false) {
-        [$page_text, $imagename, $proofer_names] = $row;
+        [$page_text, $_imagename, $_proofer_names] = $row;
         $page_texts[] = $page_text;
     }
     return $page_texts;
@@ -169,7 +169,7 @@ function join_page_texts(mysqli_result $pages_res): string
 {
     $text = "";
     while (($row = page_info_fetch($pages_res)) !== false) {
-        [$text_data, $filename, $proofer_names] = $row;
+        [$text_data, $_filename, $_proofer_names] = $row;
         $text .= $text_data . "\r\n";
     }
     return $text;
diff --git a/pinc/project_quick_check.inc b/pinc/project_quick_check.inc
index 289cf2d0b..f3a789f03 100644
--- a/pinc/project_quick_check.inc
+++ b/pinc/project_quick_check.inc
@@ -19,7 +19,7 @@ function gate_on_pqc(string $projectid): void
 
     // loop thorugh results looking for errors
     $found_error = false;
-    foreach ($results as $function => $test_result) {
+    foreach ($results as $test_result) {
         if ($test_result->status == _("Error")) {
             $found_error = true;
             break;
@@ -404,11 +404,6 @@ function _test_project_for_missing_pages(string $projectid): PQCResult
 {
     global $code_url;
 
-    $display_image_link = new_window_link(
-        "$code_url/tools/page_browser.php?project=$projectid&amp;imagefile=001.png&amp;showreturnlink=0&amp;preload=next&amp;percent=50",
-        _("Display Image")
-    );
-
     $test_name = _("Missing Pages");
     $test_desc = sprintf(
         _("This manual test requires looking through each page of a project to see if there are missing pages. This is done by looking for missing page numbers, eg: image 100.png says it's page 80 and image 101.png says it's page 82. To perform this check, you can look at the pages online from the <a href='%s'>Page Details</a> page or download the project files from the project page and check them offline. Please check to make sure all illustration images are also loaded."),
diff --git a/pinc/send_mail.inc b/pinc/send_mail.inc
index 5ef18c309..5e3a7b074 100644
--- a/pinc/send_mail.inc
+++ b/pinc/send_mail.inc
@@ -106,7 +106,6 @@ function send_mail(string $to, string $subject, string $message, ?string $from =
 
 function send_mail_project_manager(Project $project, string $info, string $prefix): bool
 {
-    $projectid = $project->projectid;
     $nameofwork = $project->nameofwork;
     $username = $project->username;
     configure_gettext_for_user($username);
diff --git a/pinc/showavailablebooks.inc b/pinc/showavailablebooks.inc
index a85c280ab..b0738dd95 100644
--- a/pinc/showavailablebooks.inc
+++ b/pinc/showavailablebooks.inc
@@ -501,8 +501,6 @@ function show_project_listing(
     // Show email addresses for site administrators
     $show_email = user_is_a_sitemanager();
 
-    $rownum = 0;
-
     while ($book = mysqli_fetch_assoc($result)) {
         echo "<tr>";
 
@@ -587,7 +585,6 @@ function show_project_listing(
         }
 
         echo "</tr>\n";
-        $rownum++;
     }
 
     echo "</table>";
@@ -708,8 +705,7 @@ function process_sorting_control(
         // Check column & convert to sql...
 
         // Find the entry in $columns whose $ext_sort_col matches $curr_ext_sort_col.
-        foreach ($columns as $col_id => $col_info) {
-            [$ext_sort_col, $label] = $col_info;
+        foreach ($columns as $col_id => [$ext_sort_col, $_label]) {
             if ($ext_sort_col == $curr_ext_sort_col) {
                 $curr_sql_sort_col = $col_id;
                 break;
diff --git a/pinc/site_news.inc b/pinc/site_news.inc
index 33b443767..d1c47a260 100644
--- a/pinc/site_news.inc
+++ b/pinc/site_news.inc
@@ -61,8 +61,6 @@ function show_news_for_page(string $news_page_id): void
 
     $user_locale = get_desired_language();
 
-    $news_subject = get_news_subject($news_page_id);
-
     // -------------------------------------------
 
     // Get the set of 'current' news items defined for the given page.
diff --git a/pinc/special_colors.inc b/pinc/special_colors.inc
index a236ab16e..6b54fbe1a 100644
--- a/pinc/special_colors.inc
+++ b/pinc/special_colors.inc
@@ -176,7 +176,6 @@ function echo_special_legend(string $projects_where_clause): void
     // now append the hard-coded special day names
     $day_array = array_merge($day_array, array_values(load_common_special_days()));
 
-    $specs_count = count($day_array);
     echo "<h3>" . html_safe($legend_text) . "</h3>";
     echo "<p><a href='$code_url/tools/project_manager/show_specials.php'>" . _("View all Special Days") . "</a></p>";
 
diff --git a/pinc/theme.inc b/pinc/theme.inc
index 5d48358ef..c647dfbee 100644
--- a/pinc/theme.inc
+++ b/pinc/theme.inc
@@ -46,7 +46,7 @@ function output_header(string $nameofpage, bool $show_statsbar = false, array $e
             // * A 1% column with the rounded corner
             // * A 74% width column for the main page content, and return.
             echo "<div id='statsbar' class='left-statsbar'>\n";
-            html_statsbar($nameofpage);
+            html_statsbar();
             echo "</div>\n";
             echo "<div id='rounded-corner' class='left-statsbar'></div>\n";
             echo "<div id='content-container' class='left-statsbar'>\n";
@@ -63,10 +63,10 @@ function output_header(string $nameofpage, bool $show_statsbar = false, array $e
 
     // Call output_footer when the main page content has been emitted so we can
     // close the table and emit the footer.
-    register_shutdown_function('output_footer', $nameofpage, $show_statsbar);
+    register_shutdown_function(output_footer(...), $show_statsbar);
 }
 
-function output_footer(string $nameofpage, bool $show_statsbar = true): void
+function output_footer(bool $show_statsbar = true): void
 {
     global $code_url, $PAGE_START_TIME;
 
@@ -82,7 +82,7 @@ function output_footer(string $nameofpage, bool $show_statsbar = true): void
         // * A 25% width column with the stats bar in it
         echo "<div id='rounded-corner' class='right-statsbar'></div>\n";
         echo "<div id='statsbar'>\n";
-        html_statsbar($nameofpage);
+        html_statsbar();
         echo "</div>\n";
     }
     // Finally close the table, and emit the footer.
@@ -531,7 +531,7 @@ function headerbar_text_array(array $entries): string
     return implode($divider, resolve_headerbar_entries($entries));
 }
 
-function html_statsbar(string $nameofpage): void
+function html_statsbar(): void
 {
     global $code_url, $PG_home_url;
     maybe_show_language_selector();
diff --git a/pinc/unicode.inc b/pinc/unicode.inc
index 42ede1ee0..cdc6a944b 100644
--- a/pinc/unicode.inc
+++ b/pinc/unicode.inc
@@ -492,7 +492,7 @@ function get_utf8_to_ascii_codepoints(): array
 function get_disallowed_codepoints(): array
 {
     $invalid_codepoints = [];
-    foreach (get_utf8_to_ascii_codepoints() as $ascii => $codepoints) {
+    foreach (get_utf8_to_ascii_codepoints() as $codepoints) {
         $invalid_codepoints = array_merge($invalid_codepoints, $codepoints);
     }
     return $invalid_codepoints;
diff --git a/pinc/upload_file.inc b/pinc/upload_file.inc
index 0a893e6e9..ad36137ae 100644
--- a/pinc/upload_file.inc
+++ b/pinc/upload_file.inc
@@ -109,7 +109,7 @@ function show_upload_form(string $form_content, string $submit_label): void
     <p>", get_big_upload_blurb(), "</p>",
     _("File to upload"), ": <input type='file' id='old_browse' accept='.zip' name='uploaded_file'>
     <input type='submit' id='old_submit' value='", attr_safe($submit_label), "'>",
-    "<p>", sprintf(_("After you click the '%s' button, the browser will appear to be slow getting to the next page. This is because it is uploading the file."), $submit_label), "</p>",
+    "<p>", $submit_blurb, "</p>",
     "</div>";
 
     // if resumable, these are shown instead
diff --git a/pinc/user_project_info.inc b/pinc/user_project_info.inc
index f5e46fed2..9ceda2b40 100644
--- a/pinc/user_project_info.inc
+++ b/pinc/user_project_info.inc
@@ -157,8 +157,7 @@ function set_user_project_event_subscription(string $username, string $projectid
 {
     assert($bit === 0 || $bit === 1);
 
-    $event_label = get_label_for_event($event);
-    // Just to ensure that $event is valid; we don't use $event_label.
+    get_label_for_event($event); // Just to ensure that $event is valid
 
     // Now that we're sure the row exists, we can update it.
     $sql = sprintf(
@@ -176,13 +175,12 @@ function set_user_project_event_subscription(string $username, string $projectid
         $bit,
         $bit
     );
-    $res = DPDatabase::query($sql);
+    DPDatabase::query($sql);
 }
 
 function user_is_subscribed_to_project_event(string $username, string $projectid, string $event): bool
 {
-    $event_label = get_label_for_event($event);
-    // Just to ensure that $event is valid; we don't use $event_label.
+    get_label_for_event($event); // Just to ensure that $event is valid
 
     $sql = sprintf(
         "
@@ -315,7 +313,7 @@ function notify_project_event_subscribers(Project $project, string $event, array
             $n_subscribers,
             DPDatabase::escape($projectid)
         );
-        $res4 = DPDatabase::query($sql4);
+        DPDatabase::query($sql4);
     }
 }
 
diff --git a/pinc/wordcheck_engine.inc b/pinc/wordcheck_engine.inc
index 40b1e029e..f74e193e3 100644
--- a/pinc/wordcheck_engine.inc
+++ b/pinc/wordcheck_engine.inc
@@ -394,7 +394,7 @@ function get_bad_words_via_external_checker($input_words_w_freq, $languages)
 
     // Now merge all misspellings by language script together
     $finalMisspellings = [];
-    foreach ($misspellings as $lang_script => $words) {
+    foreach ($misspellings as $words) {
         $finalMisspellings = array_merge($finalMisspellings, $words);
     }
     unset($misspellings);
@@ -469,7 +469,7 @@ function get_bad_words_with_diacritical_markup($input_words_w_freq): array
  */
 function get_bad_words_via_pattern($input_words_w_freq, $languages)
 {
-    [$langcode3s, $messages] = get_langcode3s_for_languages($languages);
+    [$langcode3s, $_messages] = get_langcode3s_for_languages($languages);
 
     $badWords = [];
 
@@ -816,9 +816,7 @@ function load_project_good_word_suggestions(string $projectid, int $start_time =
         return $wordsArray;
     }
 
-    foreach ($eventArray as $event) {
-        [$time, $round, $page, $proofer, $words] = $event;
-
+    foreach ($eventArray as [$_time, $round, $page, $_proofer, $words]) {
         if (count($words)) {
             if (!isset($wordsArray[$round][$page])) {
                 $wordsArray[$round][$page] = [];
@@ -836,7 +834,7 @@ function load_project_good_word_suggestions(string $projectid, int $start_time =
 function load_site_good_words_given_project(string $projectid): array
 {
     $languages = get_project_languages($projectid);
-    [$langcode3s, $messages] = get_langcode3s_for_languages($languages);
+    [$langcode3s, $_messages] = get_langcode3s_for_languages($languages);
     return load_site_good_words($langcode3s);
 }
 
@@ -844,7 +842,7 @@ function load_site_good_words_given_project(string $projectid): array
 function load_site_bad_words_given_project(string $projectid): array
 {
     $languages = get_project_languages($projectid);
-    [$langcode3s, $messages] = get_langcode3s_for_languages($languages);
+    [$langcode3s, $_messages] = get_langcode3s_for_languages($languages);
     return load_site_bad_words($langcode3s);
 }
 
@@ -852,7 +850,7 @@ function load_site_bad_words_given_project(string $projectid): array
 function load_site_possible_bad_words_given_project(string $projectid): array
 {
     $languages = get_project_languages($projectid);
-    [$langcode3s, $messages] = get_langcode3s_for_languages($languages);
+    [$langcode3s, $_messages] = get_langcode3s_for_languages($languages);
     return load_site_possible_bad_words($langcode3s);
 }
 
@@ -1274,7 +1272,6 @@ function get_all_words_in_text(string $text, bool $with_offsets = false)
     if ($with_offsets) {
         $result = [];
         foreach ($matches[0] as [$word, $offset_bytes]) {
-            $search_offset = 0;
             // offsets from preg_match_all() are in bytes, but we need the
             // offset in characters
             $offset = UTF8::strlen(substr($text, 0, $offset_bytes));
diff --git a/project.php b/project.php
index f8cc36cab..7863c0834 100644
--- a/project.php
+++ b/project.php
@@ -596,7 +596,6 @@ function do_project_info_table(): void
     if ($detail_level >= 4) {
         // We'll call do_page_table later, so we don't need the "Page Detail" link.
     } else {
-        $detail = "";
         if ($project->pages_table_exists) {
             $url = "$code_url/tools/project_manager/page_detail.php?project=$projectid&amp;show_image_size=0";
             $blurb = html_safe(_("Images, Pages Proofread, & Differences"));
@@ -670,8 +669,6 @@ function do_project_info_table(): void
 
     // --------
 
-    $comments = $project->comments;
-
     // insert e.g. templates and biographies
     $comments = parse_project_comments($project);
 
@@ -1114,7 +1111,7 @@ function do_holds(): void
     echo "</tr>\n";
 
     $disabled = $project->can_be_managed_by_current_user ? '' : 'disabled';
-    foreach (array_chunk(Project::get_holdable_states(), 2) as $set => $states) {
+    foreach (array_chunk(Project::get_holdable_states(), 2) as $states) {
         [$round_id] = explode(".", $states[0]);
         echo "<tr>\n";
         echo "<th>", $round_id, "</th>\n";
@@ -2020,15 +2017,10 @@ function do_change_state(): void
     // This can leave an extra &, but I suspect browsers can handle it.
 
     foreach ($valid_transitions as $transition) {
-        // Used for disabling the button
-        $optional_btn_attr = "";
-
         // By default say who is allowed to do this transition.
         $text_next_to_btn = " [$transition->who_restriction]";
 
         if ($transition->is_disabled($project)) {
-            $optional_btn_attr = "disabled";
-
             // Gray out the original text and add an explanation why it is disabled
             $reason = $transition->why_disabled($project);
             $text_next_to_btn = "<span class='transition-disabled'>$text_next_to_btn</span> [$reason]";
@@ -2055,7 +2047,6 @@ function do_change_state(): void
 function do_page_summary(): void
 {
     global $project;
-    $projectid = $project->projectid;
 
     if (!$project->pages_table_exists) {
         return;
diff --git a/quiz/generic/wizard/output.php b/quiz/generic/wizard/output.php
index b4e292239..7579dac10 100644
--- a/quiz/generic/wizard/output.php
+++ b/quiz/generic/wizard/output.php
@@ -128,7 +128,7 @@ function make_output(): string
     }
     $out .= "\n\n";
     $out .= "// error checks\n\n";
-    foreach ($_SESSION['quiz_data']['tests'] as $key => $test) {
+    foreach ($_SESSION['quiz_data']['tests'] as $test) {
         $out .= '$tests[] = array("type" => "' . $test['type'] .'"';
         if ($test['type'] == 'multioccurrence') {
             $out .= ', "searchtext" => "' . ssqs(sdbsn($test['searchtext'])) .'", "case_sensitive" => ';
diff --git a/stats/includes/member.inc b/stats/includes/member.inc
index c752f91f5..5bc55c37e 100644
--- a/stats/includes/member.inc
+++ b/stats/includes/member.inc
@@ -506,7 +506,7 @@ function showMbrNeighbors(User $user, string $tally_name): void
             $user,
             max($user->u_neigh, 4)
         );
-    foreach ($neighbors as $rel_posn => $neighbor) {
+    foreach ($neighbors as $neighbor) {
         $rank = $neighbor->current_page_tally_rank;
         $pagescompleted = number_format($neighbor->current_page_tally);
 
diff --git a/stats/misc_stats1.php b/stats/misc_stats1.php
index 6f481f627..2f20a07ac 100644
--- a/stats/misc_stats1.php
+++ b/stats/misc_stats1.php
@@ -96,7 +96,6 @@ function show_top_days(int $limit, string $when): void
 
     switch ($when) {
         case 'ever':
-            $where = '';
             $sub_title = sprintf(_('Top %d Proofreading Days Ever'), $limit);
             break;
 
diff --git a/tasks.php b/tasks.php
index c044da2c2..250b73658 100644
--- a/tasks.php
+++ b/tasks.php
@@ -1643,7 +1643,7 @@ function insert_related_task(int $task1, int $task2): void
         $task_id_1,
         $task_id_2
     );
-    $result = DPDatabase::query($sql);
+    DPDatabase::query($sql);
 }
 
 function remove_related_task(int $task1, int $task2): void
@@ -1661,7 +1661,7 @@ function remove_related_task(int $task1, int $task2): void
         $task_id_1,
         $task_id_2
     );
-    $result = DPDatabase::query($sql);
+    DPDatabase::query($sql);
 }
 
 function RelatedPostings(int $tid): void
diff --git a/tools/project_manager/add_files.php b/tools/project_manager/add_files.php
index f08890729..30226d828 100644
--- a/tools/project_manager/add_files.php
+++ b/tools/project_manager/add_files.php
@@ -274,7 +274,7 @@ public function analyze(): void
         }
 
         foreach (array_keys($db_entries) as $db_image_file) {
-            [$base, $ext] = split_filename($db_image_file);
+            [$base, $_ext] = split_filename($db_image_file);
             $page_related_bases[$base] = 1;
         }
 
@@ -289,7 +289,7 @@ public function analyze(): void
         $page_files = [];
         $this->non_page_files = [];
         foreach ($loadable_files as $loadable_file) {
-            [$base, $ext] = split_filename($loadable_file);
+            [$base, $_ext] = split_filename($loadable_file);
             if (array_key_exists($base, $page_related_bases)) {
                 $page_files[] = $loadable_file;
             } else {
@@ -536,7 +536,7 @@ public function _check_file(string $filename): string
 
         $ALLOWED_EXTENSIONS = ['.txt', '.png', '.jpg'];
 
-        [$base, $ext] = split_filename($filename);
+        [$_base, $ext] = split_filename($filename);
         if (!in_array($ext, $ALLOWED_EXTENSIONS)) {
             return _('filename has unrecognized suffix');
         }
diff --git a/tools/project_manager/bad_bytes_explainer.php b/tools/project_manager/bad_bytes_explainer.php
index b6193d502..7efa0d362 100644
--- a/tools/project_manager/bad_bytes_explainer.php
+++ b/tools/project_manager/bad_bytes_explainer.php
@@ -159,8 +159,7 @@ function show_a_table_of_bads(string $desired_badness): void
         </tr>
     ";
     global $_bad_byte_sequences;
-    foreach ($_bad_byte_sequences as $raw => $remarks) {
-        [$code_point, $why_bad] = $remarks;
+    foreach ($_bad_byte_sequences as $raw => [$_code_point, $why_bad]) {
         if (str_starts_with($desired_badness, '/')) {
             $matches = preg_match($desired_badness, $why_bad);
         } else {
diff --git a/tools/project_manager/diff.php b/tools/project_manager/diff.php
index db2c60216..59e50b9db 100644
--- a/tools/project_manager/diff.php
+++ b/tools/project_manager/diff.php
@@ -335,7 +335,6 @@ function can_see_names_for_page(string $projectid, string $image): bool
 function can_navigate_by_proofer(string $projectid, string $L_user): bool
 {
     global $pguser;
-    $answer = false;
     // If user isn't logged in, they definitely can't
     if ($pguser == '') {
         return false;
diff --git a/tools/project_manager/editproject.php b/tools/project_manager/editproject.php
index 4e6e8007c..6bb4283fd 100644
--- a/tools/project_manager/editproject.php
+++ b/tools/project_manager/editproject.php
@@ -480,7 +480,6 @@ public function show_visible_controls(): void
         $can_set_difficulty_tofrom_beginner = ($pguser == "BEGIN") || user_is_a_sitemanager();
 
         $can_edit_PPer = true;
-        $is_checked_out = false;
         if (!empty($this->project->projectid)) {
             $this->row(_("Project ID"), html_safe($this->project->projectid));
 
@@ -490,12 +489,10 @@ public function show_visible_controls(): void
             } elseif ($this->project->state == PROJ_POST_FIRST_CHECKED_OUT) {
                 // once the project is in PP, PPer can only be changed by an SA, PF,
                 // or if it's checked out to the PM
-                $is_checked_out = true;
                 $can_edit_PPer = (($this->project->username == $this->project->checkedoutby) ||
                                    user_is_a_sitemanager() ||
                                    user_is_proj_facilitator());
             } elseif ($this->project->state == PROJ_POST_SECOND_CHECKED_OUT) {
-                $is_checked_out = true;
                 $can_edit_PPer = user_is_a_sitemanager();
             }
         }
diff --git a/tools/project_manager/handle_bad_page.php b/tools/project_manager/handle_bad_page.php
index 9f39146d5..ff935bf8a 100644
--- a/tools/project_manager/handle_bad_page.php
+++ b/tools/project_manager/handle_bad_page.php
@@ -305,7 +305,6 @@ function update_image(string $projectid, string $image): void
     global $projects_dir;
 
     $org_image_ext = substr($image, -4);
-    $org_image_basename = basename($image, $org_image_ext);
     $tmp_image_ext = substr($_FILES['image_upload']['name'], -4);
 
     if ($tmp_image_ext == ".png" || $tmp_image_ext == ".jpg") {
diff --git a/tools/project_manager/show_current_flagged_words.php b/tools/project_manager/show_current_flagged_words.php
index 4054498d2..2a692f1bf 100644
--- a/tools/project_manager/show_current_flagged_words.php
+++ b/tools/project_manager/show_current_flagged_words.php
@@ -139,14 +139,12 @@
 /** @return list{array<string, int>, string[]} */
 function _get_current_flagged_word_list(string $projectid): array
 {
-    $messages = [];
-
     // get the latest project text of all pages up to last possible round
     $pages_res = page_info_query($projectid, Rounds::get_last()->id, 'LE');
     $page_texts = get_page_texts($pages_res);
 
     // now run it through WordCheck
-    [$bad_words_w_freq, $languages, $messages] =
+    [$bad_words_w_freq, $_languages, $messages] =
         get_bad_word_freqs_for_project_text($page_texts, $projectid, get_project_languages($projectid));
 
     // multisort screws up all-numeric words so we need to preprocess first
diff --git a/tools/project_manager/show_good_word_suggestions.php b/tools/project_manager/show_good_word_suggestions.php
index 0acdead66..f9912f8d6 100644
--- a/tools/project_manager/show_good_word_suggestions.php
+++ b/tools/project_manager/show_good_word_suggestions.php
@@ -277,7 +277,7 @@ function _get_suggestions_word_list(string $projectid, int $timeCutoff): array
     // it is in the format: $suggestions[$round][$pagenum]=$wordsArray
     foreach ($suggestions as $round => $pageArray) {
         $round_suggestions = [];
-        foreach ($pageArray as $page => $words) {
+        foreach ($pageArray as $words) {
             // add the words to the per-round array
             $round_suggestions = array_merge($round_suggestions, $words);
 
diff --git a/tools/project_manager/show_project_stealth_scannos.php b/tools/project_manager/show_project_stealth_scannos.php
index 44b0e0dac..2061658ce 100644
--- a/tools/project_manager/show_project_stealth_scannos.php
+++ b/tools/project_manager/show_project_stealth_scannos.php
@@ -178,8 +178,6 @@ function _get_stealth_scanno_word_list(string $projectid): array
     $ocr_filename = "$temp_dir/{$projectid}_ocr.txt";
     $latest_filename = "$temp_dir/{$projectid}_latest.txt";
 
-    $messages = [];
-
     // get the OCR text
     // Note: If the code is changed to allow selecting of arbitrary round text
     //       instead of just the OCR round, edit_project_word_lists.php should
@@ -308,7 +306,7 @@ function _get_stealth_scanno_word_list(string $projectid): array
     $text_to_check = implode(" ", $possible_scannos);
 
     // run the list through WordCheck to see which it would flag
-    [$possible_scannos_via_wordcheck, $languages, $messages] =
+    [$possible_scannos_via_wordcheck, $_languages, $messages] =
         get_bad_word_freqs_for_project_text($text_to_check, $projectid, get_project_languages($projectid));
 
     // load site words
diff --git a/tools/project_manager/word_freq_table.inc b/tools/project_manager/word_freq_table.inc
index d0ebd44d9..65c70fcb2 100644
--- a/tools/project_manager/word_freq_table.inc
+++ b/tools/project_manager/word_freq_table.inc
@@ -296,7 +296,7 @@ function _get_word_context_from_text(string $page_text, string $contextWord): ar
     $lineNum = 1;
     foreach ($lines as $line) {
         $words = get_all_words_in_text($line, true);
-        foreach ($words as $offset => $word) {
+        foreach ($words as $word) {
             if ($word === $contextWord) {
                 $contexts[$lineNum] = $line;
             }
diff --git a/tools/proofers/my_suggestions.php b/tools/proofers/my_suggestions.php
index 217462c3c..104e89e67 100644
--- a/tools/proofers/my_suggestions.php
+++ b/tools/proofers/my_suggestions.php
@@ -18,7 +18,7 @@
     }
 }
 
-$round_view_options = get_view_options($username);
+$round_view_options = get_view_options();
 
 // Get changes to the round views. If not set, we
 // pull the last selected option from UserSettings.
@@ -84,7 +84,7 @@
         echo "<p>$explain_why</p>";
     }
 
-    output_suggestion_table($projects, $colspecs, $username);
+    output_suggestion_table($projects, $colspecs);
 }
 
 if ($verbose) {
@@ -162,7 +162,7 @@ function get_table_column_specs(): array
 // to make sure that some projects are displayed, iterate over the view order
 
 /** @return array<string, array{label: string, text_none: string, text_verbose: string}> */
-function get_view_options(string $username): array
+function get_view_options(): array
 {
     return [
         "impact" => [
@@ -213,19 +213,15 @@ function show_page_menu(array $all_view_modes, string $round_view, string $usern
 }
 
 /** @param array<string, array{class?: string, label: string}> $colspecs */
-function show_headings(array $colspecs, string $username): void
+function show_headings(array $colspecs): void
 {
     echo "<tr>\n";
-    foreach ($colspecs as $col_id => $colspec) {
+    foreach ($colspecs as $colspec) {
         $class = '';
         if (isset($colspec['class'])) {
             $class = sprintf("class='%s'", $colspec['class']);
         }
         echo "<th $class>";
-        $qs_username = "";
-        if ($username != User::current_username()) {
-            $qs_username = "username=" . urlencode($username) . '&amp;';
-        }
         echo $colspec['label'];
         echo "</th>";
     }
@@ -236,13 +232,13 @@ function show_headings(array $colspecs, string $username): void
  * @param array<string, mixed>[] $projects
  * @param array<string, array{class?: string, label: string}> $colspecs
  */
-function output_suggestion_table(array $projects, array $colspecs, string $username): void
+function output_suggestion_table(array $projects, array $colspecs): void
 {
     global $code_url;
 
     echo "<table class='themed theme_striped' style='width: auto;'>";
 
-    show_headings($colspecs, $username);
+    show_headings($colspecs);
 
     foreach ($projects as $row) {
         echo "<tr>\n";
diff --git a/tools/proofers/preview.inc b/tools/proofers/preview.inc
index 9d31406f1..ace79cbba 100644
--- a/tools/proofers/preview.inc
+++ b/tools/proofers/preview.inc
@@ -7,13 +7,10 @@ function output_preview_div(): void
 
     $quit = attr_safe(_("Quit"));
     $configure = attr_safe(_("Configure"));
-    $add_font = attr_safe(_("Add Font"));
-    $remove_font = attr_safe(_("Remove Font"));
     $ok = attr_safe(_("OK"));
     $cancel = attr_safe(_("Cancel"));
     $some_suppressed = attr_safe(_('Some warnings are suppressed'));
     $color_markup = html_safe(_("Color markup"));
-    $image = html_safe(_("Image"));
     $text = html_safe(_("Text"));
     $font = html_safe(_("Font"));
     $tags = html_safe(_("Tags"));
@@ -21,12 +18,10 @@ function output_preview_div(): void
     $re_wrap = html_safe(_("Re-wrap"));
     $issues = html_safe(_("Issues"));
     $poss_iss = html_safe(_("Poss. Issues"));
-    $other_tags = html_safe(_("Other tags"));
     $allow_underine = html_safe(_("Allow <u> for underline"));
     $math_preview = html_safe(_("Preview Math"));
     $suppress_warnings = html_safe(_('Suppress warnings'));
     $choose_colors = html_safe(_("Choose Colors"));
-    $select = html_safe(_("Select"));
     $options = html_safe(_("Options"));
     $initial_mode = html_safe(_("Initial view mode"));
     $char_before_start = html_safe(_("Character or punctuation before inline start tag"));
diff --git a/tools/proofers/proof_frame_enh.inc b/tools/proofers/proof_frame_enh.inc
index 5f8e0f7fa..4f3f8a28d 100644
--- a/tools/proofers/proof_frame_enh.inc
+++ b/tools/proofers/proof_frame_enh.inc
@@ -89,7 +89,6 @@ function echo_proof_frame_enh(PPage $ppage): void
 
 function echo_button_menu(PPage $ppage): void
 {
-    $user = User::load_current();
     $proofreading_font_faces = get_available_proofreading_font_faces();
     $proofreading_font_sizes = get_available_proofreading_font_sizes();
     $font_family_fallback = get_proofreading_font_family_fallback();
diff --git a/tools/proofers/spellcheck_text.inc b/tools/proofers/spellcheck_text.inc
index 4fa1a7424..be272b770 100644
--- a/tools/proofers/spellcheck_text.inc
+++ b/tools/proofers/spellcheck_text.inc
@@ -20,8 +20,6 @@ use voku\helper\UTF8;
  *   Original text to run through dictionary
  * @param string $projectid
  *   Id of projected, needed for temp filename and to load the custom dictionaries
- * @param string $imagefile
- *   Image filename, needed for temp filename
  * @param string[] $languages
  *   Languages to check against
  * @param string[] $accepted_words
@@ -29,7 +27,7 @@ use voku\helper\UTF8;
  *
  * @return list{string, string[], string[], array<string, string>}
  */
-function spellcheck_text(string $orig_text, string $projectid, string $imagefile, array $languages, array $accepted_words): array
+function spellcheck_text(string $orig_text, string $projectid, array $languages, array $accepted_words): array
 {
     global $puncCharacters;
 
@@ -71,7 +69,7 @@ function spellcheck_text(string $orig_text, string $projectid, string $imagefile
 
     // Prepare the style block which requires some dynamic content from
     // the user's preferences and the page itself.
-    [$font_style, $font_size, $font_family] = get_user_proofreading_font();
+    [$_font_style, $font_size, $font_family] = get_user_proofreading_font();
     if ($font_size != '') {
         $font_size = "font-size: $font_size";
     } else {
@@ -114,7 +112,7 @@ function spellcheck_text(string $orig_text, string $projectid, string $imagefile
 
         $newLine = $origLine;
 
-        $lineIndex = $indexArray = [];
+        $indexArray = [];
 
         // find the index for each punctuation
         for ($lineIndex = 0; $lineIndex < UTF8::strlen($origLine); $lineIndex++) {
@@ -333,7 +331,7 @@ function spellcheck_apply_corrections(): array
                 continue;
             }
             // hidden values line|offset|word length
-            [$orig_line_i, $orig_word_offset, $orig_word_length] =
+            [$orig_line_i, $orig_word_offset, $_orig_word_length] =
                 explode('|', $_POST['posit'.$i]);
 
             if (!isset($offsetList[$orig_line_i])) {
@@ -430,7 +428,7 @@ function output_wordcheck_interface(User $user, PPage $ppage, string $text_data,
 
     // run the text through the spellcheck - returns the form contents and a list of languages the page was checked against
     [$page_contents, $languages, $messages, $highlights] =
-        spellcheck_text($text_data, $ppage->projectid(), $ppage->imagefile(), $languages, $accepted_words);
+        spellcheck_text($text_data, $ppage->projectid(), $languages, $accepted_words);
 
     if (!$languages) {
         $messages[] = _("No check against a dictionary has been made.");
@@ -493,7 +491,7 @@ function output_wordcheck_interface(User $user, PPage $ppage, string $text_data,
         // get a list of languages with dictionaries installed on the system
         $dict_list = get_languages_with_dictionaries();
         asort($dict_list);
-        foreach ($dict_list as $langcode => $language) {
+        foreach ($dict_list as $language) {
             // skip the languages that we just used.
             if (in_array($language, $languages)) {
                 continue;
diff --git a/tools/site_admin/copy_pages.php b/tools/site_admin/copy_pages.php
index 4d00db0fd..13661ec02 100644
--- a/tools/site_admin/copy_pages.php
+++ b/tools/site_admin/copy_pages.php
@@ -49,7 +49,6 @@
     case 'showform':
         display_copy_pages_form(
             $projectid_,
-            $from_image_,
             $transfer_notifications,
             $add_deletion_reason,
             $merge_wordcheck_data,
@@ -62,7 +61,6 @@
     case 'showagain':
         display_copy_pages_form(
             $projectid_,
-            $from_image_,
             $transfer_notifications,
             $add_deletion_reason,
             $merge_wordcheck_data,
@@ -146,11 +144,9 @@
 
 /**
  * @param array{from: string, to: string} $projectid_
- * @param array{lo: string, hi: string} $from_image_
  */
 function display_copy_pages_form(
     ?array $projectid_,
-    ?array $from_image_,
     bool $transfer_notifications,
     bool $add_deletion_reason,
     bool $merge_wordcheck_data,
@@ -458,7 +454,6 @@ function ($a, $b) {
     // The c_ prefix means that it only pertains to *copied* pages.
 
     $c_src_image_ = [];
-    $c_src_fileid_ = [];
     $c_dst_image_ = [];
     $c_dst_fileid_ = [];
 
@@ -469,7 +464,6 @@ function ($a, $b) {
         $c_dst_image = $c_src_image;
 
         $c_src_image_[] = $c_src_image;
-        $c_src_fileid_[] = $c_src_fileid;
         $c_dst_image_[] = $c_dst_image;
         $c_dst_fileid_[] = $c_dst_fileid;
     }
@@ -585,7 +579,6 @@ function ($a, $b) {
 
     for ($j = 0; $j < $n_pages_to_copy; $j++) {
         $c_src_image = $c_src_image_[$j];
-        $c_src_fileid = $c_src_fileid_[$j];
         $c_dst_image = $c_dst_image_[$j];
         $c_dst_fileid = $c_dst_fileid_[$j];
 
diff --git a/tools/site_admin/delete_pages.php b/tools/site_admin/delete_pages.php
index c79b5796c..13c7d5263 100644
--- a/tools/site_admin/delete_pages.php
+++ b/tools/site_admin/delete_pages.php
@@ -129,7 +129,7 @@ function delete_pages(?string $projectid, ?array $from_image_, bool $just_checki
 
     validate_projectID($projectid);
     $res = DPDatabase::query("
-        SELECT image, fileid
+        SELECT image
         FROM $projectid
         ORDER BY image
     ");
@@ -143,7 +143,7 @@ function delete_pages(?string $projectid, ?array $from_image_, bool $just_checki
     }
 
     $all_image_values = [];
-    while ([$image, $fileid] = mysqli_fetch_row($res)) {
+    while ([$image] = mysqli_fetch_row($res)) {
         $all_image_values[] = $image;
     }
 
diff --git a/tools/site_admin/manage_site_access_privileges.php b/tools/site_admin/manage_site_access_privileges.php
index 76a8aa5c6..71a0d8aa2 100644
--- a/tools/site_admin/manage_site_access_privileges.php
+++ b/tools/site_admin/manage_site_access_privileges.php
@@ -156,8 +156,6 @@ function update_settings(User $user, Settings $user_settings): void
 {
     global $boolean_user_settings, $value_user_settings, $freeform_user_settings, $pguser;
 
-    $username = $user->username;
-
     $disposition = [
         'turn on' => [],
         'turn off' => [],
diff --git a/tools/site_admin/manage_site_word_lists.php b/tools/site_admin/manage_site_word_lists.php
index ffde14043..a1620bef7 100644
--- a/tools/site_admin/manage_site_word_lists.php
+++ b/tools/site_admin/manage_site_word_lists.php
@@ -216,7 +216,7 @@ function manage_site_word_lists_handle_action($action, $list_type, $language, $w
             // save the list if requested
 
             // if the $site_words_dir doesn't exist already, create it
-            [$site_words_dir, $site_words_url] = get_site_word_paths();
+            [$site_words_dir, $_site_words_url] = get_site_word_paths();
             if (!is_dir($site_words_dir) && !mkdir($site_words_dir)) {
                 throw new RuntimeException(sprintf(_("Unable to create site word list dir %s"), $site_words_dir));
             }
diff --git a/tools/site_admin/rename_pages.php b/tools/site_admin/rename_pages.php
index 9cfaa4dc7..9dd65ec02 100644
--- a/tools/site_admin/rename_pages.php
+++ b/tools/site_admin/rename_pages.php
@@ -517,9 +517,7 @@ function get_requested_name_mapping(): array
         die("nff_ param is empty");
     }
 
-    foreach ($nff_ as $k => $part_new_fileid_for_) {
-        // (Ignore $k, it doesn't convey any useful information.)
-
+    foreach ($nff_ as $part_new_fileid_for_) {
         foreach ($part_new_fileid_for_ as $old_fileid => $new_fileid) {
             assert(!isset($new_fileid_for_[$old_fileid]));
             $new_fileid_for_[$old_fileid] = $new_fileid;
diff --git a/tools/site_admin/show_common_words_from_project_word_lists.php b/tools/site_admin/show_common_words_from_project_word_lists.php
index e37b8c841..88c1d56e7 100644
--- a/tools/site_admin/show_common_words_from_project_word_lists.php
+++ b/tools/site_admin/show_common_words_from_project_word_lists.php
@@ -132,7 +132,6 @@ function _handle_action($action, $list_type, $language, $cutoff, $lang_match)
             $total_projects_with_words = 0;
 
             // figure out what kind of language matching we're going to use
-            $where_clause = "";
             switch ($lang_match) {
                 case "exact":
                     $where_clause = "language = '$language'";
diff --git a/tools/site_search.php b/tools/site_search.php
index 18b8bb4eb..b67359757 100644
--- a/tools/site_search.php
+++ b/tools/site_search.php
@@ -160,7 +160,7 @@ function get_prefix_searches(bool $flatten_aliases = false): array
     }
 
     if ($flatten_aliases) {
-        foreach ($prefix_searches as $key => &$data) {
+        foreach ($prefix_searches as &$data) {
             if (isset($data["alias"])) {
                 $alias = $data["alias"];
                 unset($data["alias"]);
@@ -262,7 +262,7 @@ function get_jump_words(bool $flatten_aliases = false): array
     }
 
     if ($flatten_aliases) {
-        foreach ($jump_words as $key => &$data) {
+        foreach ($jump_words as &$data) {
             if (isset($data["alias"])) {
                 $alias = $data["alias"];
                 unset($data["alias"]);
diff --git a/userprefs.php b/userprefs.php
index 7d70a62b1..6ffba3d56 100644
--- a/userprefs.php
+++ b/userprefs.php
@@ -76,7 +76,7 @@
     } elseif ($selected_tab == 1) {
         save_proofreading_tab($user);
     } elseif ($selected_tab == 2) {
-        save_pm_tab($user);
+        save_pm_tab();
     }
 
     if (isset($_POST["saveAndQuit"]) || isset($_POST["mkProfileAndQuit"])) {
@@ -201,7 +201,7 @@ function do_font_sample_update(font_index, size_index, layout) {
 if ($selected_tab == 1) {
     echo_proofreading_tab($user);
 } elseif ($selected_tab == 2 && user_is_PM()) {
-    echo_pm_tab($user);
+    echo_pm_tab();
 } else { // $selected _tab == 0 OR someone tried to access e.g. the PM-tab without being a PM.
     echo_general_tab($user);
 }
@@ -512,7 +512,6 @@ function echo_proofreading_tab(User $user): void
     );
     echo "</tr>\n";
 
-    $proofreading_font_faces = get_available_proofreading_font_faces();
     echo "<tr>\n";
     show_preference(
         _('Font Face'),
@@ -727,7 +726,7 @@ function save_proofreading_tab(User $user): void
     }
 }
 
-function echo_pm_tab(User $user): void
+function echo_pm_tab(): void
 {
     global $userSettings;
 
@@ -779,7 +778,7 @@ function echo_pm_tab(User $user): void
     echo_bottom_button_row();
 }
 
-function save_pm_tab(User $user): void
+function save_pm_tab(): void
 {
     global $userSettings;