Editing Hatnote/doc (section)

== Errors ==

If no hatnote text is supplied, the template will output the following message:
* {{hatnote|category=no}}

If you see this error message, it is for one of four reasons:
# No parameters were specified (the template code was <code><nowiki>{{hatnote}}</nowiki></code>). Please use <code><nowiki>{{hatnote|</nowiki>''text''<nowiki>}}</nowiki></code> instead.
# Some parameters were specified, but the hatnote text wasn't included. For example, the template text <code><nowiki>{{hatnote|extraclasses=seealso}}</nowiki></code> will produce this error. Please use (for example) <code><nowiki>{{hatnote|</nowiki>''text''<nowiki>|extraclasses=seealso}}</nowiki></code> instead.
# The hatnote text was specified, but that text contains an equals sign ("="). The equals sign has a special meaning in template code, and because of this it cannot be used in template parameters that do not specify a parameter name. For example, the template code <code><nowiki>{{hatnote|2+2=4}}</nowiki></code> will produce this error. To work around this, you can specify the parameter name explicitly by using <code>1=</code> before the hatnote text, like this: <code><nowiki>{{hatnote|1=2+2=4}}</nowiki></code>.
# You tried to access [[Module:Hatnote]] directly by using <code><nowiki>{{#invoke:hatnote|hatnote|</nowiki>''text''<nowiki>}}</nowiki></code>. Use of #invoke in this way has been disabled for performance reasons. Please use <code><nowiki>{{hatnote|</nowiki>''text''<nowiki>}}</nowiki></code> instead.

Pages that contain this error message are tracked in [[:Category:Hatnote templates with errors]].