Wordfilter

A wordfilter (sometimes referred to as just "filter" or "censor") is a script typically used on Internet forums or chat rooms that automatically scans users' posts or comments as they are submitted and automatically changes or censors particular words or phrases.

The most basic wordfilters search only for specific strings of letters, and remove or overwrite them regardless of their context. More advanced wordfilters make some exceptions for context (such as filtering "butt" but not "butter"), and the most advanced wordfilters may use regular expressions.

Wordfilters can serve any of a number of functions.

A swear filter, also known as a profanity filter or language filter is a software subsystem which modifies text to remove words deemed offensive by the administrator or community of an online forum. Swear filters are common in custom-programmed chat rooms and online video games, primarily MMORPGs. This is not to be confused with content filtering, which is usually built into internet browsing programs by third-party developers to filter or block specific websites or types of websites. Swear filters are usually created or implemented by the developers of the Internet service.

Most commonly, wordfilters are used to censor language considered inappropriate by the operators of the forum or chat room. Expletives are typically partially replaced, completely replaced, or replaced by nonsense words. This relieves the administrators or moderators of the task of constantly patrolling the board to watch for such language. This may also help the message board avoid content-control software installed on users' computers or networks, since such software often blocks access to Web pages that contain vulgar language.

Filtered phrases may be permanently replaced as it is saved (example: phpBB 1.x), or the original phrase may be saved but displayed as the censored text. In some software users can view the text behind the wordfilter by quoting the post.

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