15.3.9 Emacs Lisp Format Strings -------------------------------- Emacs Lisp format strings are documented in the Emacs Lisp reference, section Formatting Strings, <https://www.gnu.org/manual/elisp-manual-21-2.8/html_chapter/elisp_4.html#SEC75>. Note that as of version 21, XEmacs supports numbered argument specifications in format strings while FSF Emacs doesn’t.