It might be a method to avoid trigger an overenthusiastic WAF, but these are all SQL tokens and keywords. It seems far more likely that they've blocked them in

It might be a method to avoid trigger an overenthusiastic WAF, but these are all SQL tokens and keywords. It seems far more likely that they've blocked them in a desperate effort to catch injection attacks. There might not be an actual attack vector, they might block these words in all inputs. It just smells like incompetence.