Textpattern CMS Template Tags , system category

<txp:error_message />
Prints the error message text for the error status as set by the server.
<txp:error_status />
Prints the error status as returned by the server.
<txp:if_author />
Will execute the contained statements if the called page is the result of an article search by author.
<txp:if_category />
Will execute the contained statements if the name attribute matches a category search value.
<txp:if_different />
Will execute the contained statement when the value differs from the preceding value.
Will execute the contained statements if the current category is the first in the currently displayed list.
Will execute the contained statements if the current category is the last in the currently displayed list.
<txp:if_plugin />
Will execute the contained statements if the name matches a currently installed and enabled plugin.
<txp:if_search />
Will execute the contained statements if the called page is the result of a search.
Will execute the contained statements if the article list contains entries matching the search term.
<txp:if_status />
Will execute the contained statements depending on the requested page's HTTP status condition.
<txp:if_variable />
Tests the existence and/or value of a global variable set with the variable tag.