Variable: gnus-summary-gather-exclude-subject
gnus-summary-gather-exclude-subject is a customizable variable defined
in gnus-sum.el.gz.
Value
"^ *$\\|^(none)$"
Documentation
A regexp to match subjects to be excluded from loose thread gathering.
As loose thread gathering is done on subjects only, that means that there can be many false gatherings performed. By rooting out certain common subjects, gathering might become saner.
Source Code
;; Defined in /usr/src/emacs/lisp/gnus/gnus-sum.el.gz
(defcustom gnus-summary-gather-exclude-subject "^ *$\\|^(none)$"
"A regexp to match subjects to be excluded from loose thread gathering.
As loose thread gathering is done on subjects only, that means that
there can be many false gatherings performed. By rooting out certain
common subjects, gathering might become saner."
:group 'gnus-thread
:type 'regexp)