Where can I find information about all the acet- functions availables I find them but has no description of arguments to use them acet-all ( / a b) (setq ldef nil) (setq a (atoms-family 1)) (while a (setq b (substr (car a) 1 4)) (if (= (strcase b) "ACET") (setq ldef (agr_lstdef (car a) ldef)) ) (setq a (cdr a)) ) (setq ldef (vl-sort ldef '>)) ) Thanks