Variable: nnheader-numerical-files
nnheader-numerical-files is a variable defined in nnheader.el.gz.
Value
"\\([0-9]+\\)\\(\\.Z\\'\\|\\.bz2\\'\\|\\.tbz2?\\'\\|\\.\\(?:tgz\\|svgz\\|sifz\\)\\'\\|\\.g?z\\'\\|\\.lz\\'\\|\\.lzma\\'\\|\\.xz\\'\\|\\.txz\\'\\|\\.dz\\'\\|\\.zst\\'\\|\\.tzst\\'\\)?"
Documentation
Regexp that match numerical files.
Source Code
;; Defined in /usr/src/emacs/lisp/gnus/nnheader.el.gz
(defvar nnheader-numerical-files
(if (boundp 'jka-compr-compression-info-list)
(concat "\\([0-9]+\\)\\("
(mapconcat (lambda (i) (aref i 0))
jka-compr-compression-info-list "\\|")
"\\)?")
"[0-9]+$")
"Regexp that match numerical files.")