There are deuce independent methods of filtering content: by [http://en.wikipedia.org/wiki/URL URL] and/or by Keyword.

location Filtering stops the website according to its address. Filtering by Address may be hard because of the fluid nature and severity of the net. Lists of offensive site may become found across various means, & must be updated typically.

Keyword filtering blocks off the webpage whenever it contains certain offense or even restricted keywords. Keyword filtering may be problematic therein numerous words that may be considered offence own legitimate utilizes.