+=item C<%CustomFieldGroupings>
+
+This option affects the display of ticket and user custom fields in the
+web interface. It does not address the sorting of custom fields within
+the groupings; which is controlled by the Ticket Custom Fields tab in
+Queue Configuration in the Admin UI.
+
+A nested datastructure defines how to group together custom fields
+under a mix of built-in and arbitrary headings ("groupings").
+
+Set C<%CustomFieldGroupings> to a nested structure similar to the following:
+
+ Set(%CustomFieldGroupings,
+ 'RT::Ticket' => [
+ 'Grouping Name' => ['CF Name', 'Another CF'],
+ 'Another Grouping' => ['Some CF'],
+ 'Dates' => ['Shipped date'],
+ ],
+ 'RT::User' => [
+ 'Phones' => ['Fax number'],
+ ],
+ );
+
+The first level keys are record types for which CFs may be used, and the
+values are either hashrefs or arrayrefs -- if arrayrefs, then the
+ordering is preserved during display, otherwise groupings are displayed
+alphabetically. The second level keys are the grouping names and the
+values are array refs containing a list of CF names.
+
+There are several special built-in groupings which RT displays in
+specific places (usually the collapsible box of the same title). The
+ordering of these standard groupings cannot be modified. You may also
+only append Custom Fields to the list in these boxes, not reorder or
+remove core fields.
+
+For C<RT::Ticket>, these groupings are: C<Basics>, C<Dates>, C<Links>, C<People>
+
+For C<RT::User>: C<Identity>, C<Access control>, C<Location>, C<Phones>
+
+Extensions may also add their own built-in groupings, refer to the individual
+extension documentation for those.
+