Category sort keys are entered into the "[[Category:" tag by means of a piped link. If multiple categories need the same sort key, you can use the magic word "DEFAULTSORT", which uses a colon instead of a piped link, like so: {{DEFAULTSORT|sort key}}. A few different general sorting rules are applied here, but be careful – individual categories may have special rules, dependent of the topic – they will be listed on individual talk pages if they apply. Otherwise, the following situations are standard: