diff --git a/scripts/qa/check-valid-method-names.php b/scripts/qa/check-valid-method-names.php
new file mode 100644
index 000000000..8ed962737
--- /dev/null
+++ b/scripts/qa/check-valid-method-names.php
@@ -0,0 +1,139 @@
+<?php
+/*
+  +----------------------------------------------------------------------+
+  | PHP Version 8                                                        |
+  +----------------------------------------------------------------------+
+  | Copyright (c) 1997-2021 The PHP Group                                |
+  +----------------------------------------------------------------------+
+  | This source file is subject to version 3.0 of the PHP license,       |
+  | that is bundled with this package in the file LICENSE, and is        |
+  | available through the world-wide-web at the following url:           |
+  | http://www.php.net/license/3_0.txt.                                  |
+  | If you did not receive a copy of the PHP license and are unable to   |
+  | obtain it through the world-wide-web, please send a note to          |
+  | license@php.net so we can mail you a copy immediately.               |
+  +----------------------------------------------------------------------+
+  | Authors:    George Peter Banyard <girgias@php.net>                   |
+  +----------------------------------------------------------------------+
+  | Description: This file parses the manual and outputs all erroneous   |
+  |              <methodname> tag usage.                                 |
+  +----------------------------------------------------------------------+
+
+*/
+
+/* Path to the root of EN extension reference tree */
+$doc_en_root = dirname(__DIR__, 3) . '/en/reference';
+
+$total = 0;
+
+
+function isMagicMethod(string $method): bool
+{
+    switch ($method) {
+        case 'construct':
+        case 'destruct':
+        case 'tostring':
+        case 'call':
+        case 'callstatic':
+        case 'wakeup':
+        case 'sleep':
+        // case 'set': // TODO This conflicts with certain classes
+        // case 'get': // TODO This conflicts with certain classes
+        case 'isset':
+        case 'unset':
+        case 'setstate':
+        case 'clone':
+            return true;
+        default:
+            return false;
+    }
+}
+
+// TODO Need to add Predefined Interfaces/Classes
+/* make a method list from files in extension directories */
+function make_method_list(string $lang_doc_root): array
+{
+    $methods = [];
+
+    foreach (new FilesystemIterator($lang_doc_root) as $extensions) {
+        if (!$extensions->isDir() || !$extensions->isReadable()) {
+            continue;
+        }
+
+        foreach (new FilesystemIterator($extensions->getPathname()) as $extension) {
+            if (!$extension->isDir() || !$extension->isReadable()) {
+                continue;
+            }
+            // Skip functions folder
+            if ($extension->getFilename() === 'functions') {
+                continue;
+            }
+
+           $it = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($extension->getPathname(),
+                FilesystemIterator::SKIP_DOTS | FilesystemIterator::CURRENT_AS_FILEINFO));
+
+            foreach ($it as $file) {
+                if ($file->isDir() || !$file->isReadable()) {
+                    continue;
+                }
+                $class = str_replace($extension->getPath() . '/', '', $file->getPath());
+                $class = str_replace('/', '\\', $class);
+                //$class = str_replace('-', '_', $class);
+                $class = strtolower($class);
+                $method = str_replace(['-', '.'], '_', $file->getBasename('.xml'));
+                $method = strtolower($method);
+                if (isMagicMethod($method)) { $method = '__' . $method; }
+                $fqn = $class . '::' . $method;
+                $methods[$fqn] = true;
+            }
+        }
+    }
+
+    return $methods;
+}
+
+echo "Building a list of methods...\n";
+$methods =  make_method_list($doc_en_root);
+
+echo 'List complete. ' . count($methods) . " methods.\n";
+
+echo "Checking the manual for <methodname> tags that contain invalid methods...\n";
+foreach (new RecursiveIteratorIterator(new RecursiveDirectoryIterator($doc_en_root)) as $file) {
+    if ($file->isDir() || !$file->isReadable()) {
+        continue;
+    }
+
+    $isFunction = false;
+
+    $name = $file->getBasename();
+    $path = $file->getPathname();
+    if (strpos($path, '/functions/') !== false) { $isFunction = true; }
+    $contents = file_get_contents($path);
+
+    if ($contents == '') {
+        continue;
+    }
+
+    if (preg_match_all('|<methodname>(.*?)</methodname>|s', $contents, $m)
+        && is_array($m)
+        && is_array($m[1]))
+    {
+        if ($isFunction) {
+            // Unset the first entry as it is the function prototype
+            unset($m[1][0]);
+        }
+        foreach ($m[1] as $fqn) {
+            $lcFqn = strtolower(trim($fqn));
+            if (!\array_key_exists($lcFqn, $methods)) {
+                //var_dump($fqn);
+                $total++;
+                $fileout = substr($file, strlen($doc_en_root) + 1);
+
+                printf("%-60.60s  <methodname>$fqn</methodname>\n", $fileout);
+            }
+        }
+    }
+}
+echo "Found $total occurrences.\n";
+
+exit((bool) $total);