Since wordfilters are automated and look only for particular sequences of characters, users aware of the filters will sometimes try to circumvent them by changing their lettering just enough to avoid the filters. A user trying to avoid a vulgarity filter might replace one of the characters in the offending word into an asterisk, dash, or something similar. Some administrators respond by revising the wordfilters to catch common substitutions; others may make filter evasion a punishable offense of its own. A simple example of evading a wordfilter would be entering symbols between letters or using leet. More advanced techniques of wordfilter evasion include the use of images, using hidden tags, or Cyrillic characters (i.e. a homograph spoofing attack).