8.21.1 Setup

Fortunately, setting up the Gnus registry is pretty easy:

(setq gnus-registry-max-entries 2500
      gnus-registry-use-long-group-names t)

(gnus-registry-initialize)

This adds registry saves to Gnus newsrc saves (which happen on exit and when you press s from the *Group* buffer. It also adds registry calls to article actions in Gnus (copy, move, etc.) so it's not easy to undo the initialization. See gnus-registry-initialize for the gory details.

Here are other settings used by the author of the registry (understand what they do before you copy them blindly).

(setq
 gnus-registry-split-strategy 'majority
 gnus-registry-ignored-groups '(("nntp" t)
                                ("nnrss" t)
                                ("spam" t)
                                ("train" t))
 gnus-registry-max-entries 500000
 gnus-registry-use-long-group-names t
 gnus-registry-track-extra '(sender subject))

They say: keep a lot of messages around, use long group names, track messages by sender and subject (not just parent Message-ID), and when the registry splits incoming mail, use a majority rule to decide where messages should go if there's more than one possibility. In addition, the registry should ignore messages in groups that match "nntp", "nnrss", "spam", or "train."

You are doubtless impressed by all this, but you ask: "I am a Gnus user, I customize to live. Give me more." Here you go, these are the general settings.

Variable: gnus-registry-unfollowed-groups

The groups that will not be followed by gnus-registry-split-fancy-with-parent. They will still be remembered by the registry. This is a list of regular expressions.

Variable: gnus-registry-ignored-groups

The groups that will not be remembered by the registry. This is a list of regular expressions, also available through Group/Topic customization (so you can ignore or keep a specific group or a whole topic).

Variable: gnus-registry-use-long-group-names

Whether the registry will use long group names. It's recommended to set this to t, although everything works if you don't. Future functionality will require it.

Variable: gnus-registry-max-entries

The number (an integer or nil for unlimited) of entries the registry will keep.

Variable: gnus-registry-cache-file

The file where the registry will be stored between Gnus sessions.