elfeed-score maintains statistics on when & how frequently each rule matches an entry (on which more below). In earlier versions of the package, each rule’s stats were maintained in the rule structure itself & were persisted along with each rule to the score file.
This turned out to be ill-conceived, leading to split-brain when the user edited their score file with un-written stats still in memory.
Today, elfeed-score maintains a separate datastructure holding this
information & automatically writes it to disk in a separate file. The
location of the stats file is defined in
elfeed-score-rule-stats-file.
The location at which scoring rule stats are maintained.
The default value is elfeed.stats in
user-emacs-directory, which see user-emacs-directory in Emacs Lisp.
Since this file is meant to be maintained automatically by elfeed-score, this manual won’t go over the file format.