@var{element-type}. This appears in the customization buffer as a
list of elements, with @samp{[INS]} and @samp{[DEL]} buttons for adding
more elements or removing elements.
+
+@item (checklist @var{type} @dots{})
+The @var{type} arguments represent each checklist item. The value will
+be a list containing the values of all checked @var{type} arguments.
+The checklist will match a list whose elements all match at least one of
+the specified @var{type} arguments.
+
+Usually a checklist will only match if the items are in the exact
+sequence given in the specification. If you supply the additional
+arguments @code{:greedy t}, it will allow the items to come in any
+sequence. However, if you extract the value they will be in the
+sequence given in the checklist, i.e.@: the original sequence is
+forgotten.
+
+Using this type with @code{:greedy} is useful for specifying association
+or property lists with keys from a fixed set and properly-typed
+arguments.
@end table
@node Splicing into Lists