+@defmac lazy-completion-table var fun &rest args
+This macro provides a way to initialize the variable @var{var} as a
+collection for completion in a lazy way, not computing its actual
+contents until they are first needed. You use this macro to produce a
+value that you store in @var{var}. The actual computation of the
+proper value is done the first time you do completion using @var{var}.
+It is done by calling @var{fun} with the arguments @var{args}. The
+value @var{fun} returns becomes the permanent value of @var{var}.
+
+Here are two examples of use:
+
+@example
+(defvar foo (lazy-completion-table foo make-my-alist 'global))
+
+(make-local-variable 'bar)
+(setq bar (lazy-completion-table foo make-my-alist 'local)
+@end example
+@end defmac
+