If STRING has a non-nil `yank-handler' property on the first character,
the normal insert behavior is modified in various ways. The value of
-the yank-handler property must be a list with one to five elements
+the yank-handler property must be a list with one to four elements
with the following format: (FUNCTION PARAM NOEXCLUDE UNDO).
When FUNCTION is present and non-nil, it is called instead of `insert'
to insert the string. FUNCTION takes one argument--the object to insert.