Google Clarifies 503 Status Codes, Robots.txt Controls, and Bracket URL Handling

Google advises serving 503 status codes from outside PHP during patches and keeping robots.txt accessible to prevent URLs from being dropped from the index.

Google recommends returning 503 status codes instead of 404s during server maintenance to prevent indexed pages from being permanently removed from search results.

Google's Gary Illyes and Chery Prommawin released a video explaining which robots.txt directives are actually supported by Google and other search engines or AI crawlers.

John Mueller provided guidance on maintaining search visibility when temporarily taking a site offline to patch the PHP2Shell vulnerability.