(:Summary: Group Header and Group Footer page usage:)
(:Audience: authors (intermediate) :)
Every [[WikiGroup]] can have `GroupHeader and `GroupFooter pages that contain markup that should be included at the beginning or end of each page within the group. This feature is useful for:

* adding a disclaimer or heading to all of the pages of a group
* defining custom [[WikiStyles]] that may be used for all pages in a group
* replacing the default headers and/or footers for pages in a group (e.g., using [@(:noheader:)@] and or [@(:nofooter:)@] -- see [[PageDirectives]]).

To create a group header, just create a new page called [@YourGroup.GroupHeader@]. Group headers allow authors to create groups with custom headers and footers without having to coordinate with a [[wiki administrator]].  

The default `GroupHeader or `GroupFooter can be suppressed on an individual page (such as a group's `HomePage) by using the [@(:nogroupheader:)@] and [@(:nogroupfooter:)@] markups ''on that page''.

If a generic `GroupHeader is used in one wikigroup (say, the Site wikigroup), then the code can be easily duplicated in the `GroupHeader of any other group by using 
[@(:include Site.GroupHeader:)@].  See [[IncludeOtherPages]].

If you want a header or footer to appear when you print a page (action '''print'''), simply create a page called [@YourGroup.GroupPrintHeader@] or [@YourGroup.GroupPrintFooter@] and fill it with your markup.

>>faq<< [[#faq]]

Q: How do I set one header for all pages/groups?
A: The header for each page is controlled by the $GroupHeaderFmt variable.  Thus a site-wide groupheader can be added with

->[@
$GroupHeaderFmt = '(:include {$SiteGroup}.SiteHeader
                   basepage={*$FullName}:)(:nl:)' . $GroupHeaderFmt;
@]
(:comment above line split as it breaks fixed width skins:)

Note that single quotes must be used so that [@$Group@] (which is part of the default contents of $GroupHeaderFmt) will be substituted properly by PmWiki, and that this applies to all variables ending in $[@...Fmt@].
(:comment above note edited as it was breaking fixed width skins:)
See also the Cookbook:AllGroupHeader page.

A: Any form of markup is valid in $GroupHeaderFmt, thus one can do

->[@$GroupHeaderFmt .= "Global markup text here.";@]

Q: Would this then work for site footers?
->[@
$GroupFooterFmt = '(:include {$SiteGroup}.SiteFooter
                   basepage={*$FullName}:)(:nl:)' . $GroupFooterFmt;
@]