In the early days of web development, developers often constructed database queries by directly concatenating user input (the id value) into SQL commands.
The URL pattern index.php?id= is a common structure used by websites—especially those built with PHP and MySQL—to retrieve specific content from a database, such as a blog post or a product page. inurl index.php%3Fid=
Google may misinterpret ? as a search operator or ignore it. Encoding it ensures the literal ? is included in the search. In the early days of web development, developers