Filter question

[Luckyrare]

I would do it on insert for user speed & bandwidth usage.

[Jamie.]

If it was filtered on insert, and the site owner wants to change the rules about filtering e.g. another word is added to the filter database, then he would have to go through the whole database and edit it. OR filter on output.

No I would imagine if he was to use this idea then there would be an option to filter it or not then it would just skip that piece of coding without filtering