Document add-to-history.

diff --git a/etc/NEWS b/etc/NEWS
index 378f715b2867ee4ec7244e7bf965d323e82178fd..2d6675b1e72c938bcc15d6b63838381ab0e929f8 100644 (file)
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -3557,6 +3557,17 @@ It modifies the list destructively, like `delete'.  Of several `equal'
 occurrences of an element in the list, the one that's kept is the
 first one.
 
++++
+*** New function `add-to-history' adds an element to a history list.
+
+By default it removes duplicate elements from the history list it
+updates, but if `history-delete-duplicates' is nil or the function's
+optional argument KEEP-DUPS is non-nil, duplicate elements are not
+removed.
+
+Lisp packages should use this function to add elements to their
+history lists.
+
 +++
 *** New function `rassq-delete-all'.