one of the documented procedures in this installation of the ACS
ad_scope_page_title   page_title   db   { show_logo_p "1" }
What it does:
if scope is not set in the topmost environment then public scope is assumed. if scope is group, it assumes group_vars_set is set in the topmost environment. it returns properly formatted page title for the appropriate scope. depending on settings it may display the logo. if show_logo_p is 1, logo will be displayed (given that the logo is enabled for this page), else logo will not be displayed.
Defined in: /web/philip/tcl/ad-scope.tcl

Source code:

    if { [uplevel [ad_scope_upvar_level] {info exists scope}] } {
	upvar [ad_scope_upvar_level] scope scope
    } else {
	set scope public

    switch $scope {
	public {
	    return "<h2>$page_title</h2>"
	group {
	    upvar [ad_scope_upvar_level] group_vars_set group_vars_set
	    set group_id [ns_set get $group_vars_set group_id]
	    set group_name [ns_set get $group_vars_set group_name]
	    return [ug_page_title $page_title $db $group_id $group_name $show_logo_p]
	user {
	    # this may be later modified if we allow users to customize the display of their pages
	    return "<h2>$page_title</h2>"