Some signatures might be the user's name in an ASCII format, while others could be links to their blog, a humourous quote, or a board they frequent.
Users must take care when creating or changing their signature, as a ToS violation in a signature will result in a Sig Wipe which comes packaged with a warning and a loss of 10 karma. Lead Moderators and Administrators have a sig-wipe tool that can remove violating signatures from posts without removing the whole message. To divide a signature from the rest of the post, the user must use the standard "---". If they don't, there is a high chance that they will be moderated.