gnus: Registry Article Refer Method
9.18.2 Fetching by ‘Message-ID’ Using the Registry
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The registry knows how to map each ‘Message-ID’ to the group it’s in.
This can be leveraged to enhance the “article refer method”, the thing
that tells Gnus how to look up an article given its Message-ID (
Finding the Parent).
The ‘nnregistry’ refer method does exactly that. It has the
advantage that an article may be found regardless of the group it’s
in—provided its ‘Message-ID’ is known to the registry. It can be
enabled by augmenting the start-up file with something along these
lines:
;; Keep enough entries to have a good hit rate when referring to an
;; article using the registry. Use long group names so that Gnus
;; knows where the article is.
(setq gnus-registry-max-entries 2500)
(gnus-registry-initialize)
(setq gnus-refer-article-method
'(current
(nnregistry)
(nnweb "gmane" (nnweb-type gmane))))
The example above instructs Gnus to first look up the article in the
current group, or, alternatively, using the registry, and finally, if
all else fails, using Gmane.