Correct, this behavior is well-known and has been around for 20+ years. Leading spaces are removed and additionally other spaces or dots are converted to an und

Correct, this behavior is well-known and has been around for 20+ years. Leading spaces are removed and additionally other spaces or dots are converted to an underscore. For this reason, many frameworks ignore the default $_GET structure and instead access the raw URI query in $_SERVER['QUERY_STRING'].