howto/git.md

@@ -242,6 +242,49 @@ Some repositories are mirrored to https://github.com/torproject
 organization and to the https://gitlab.torproject.org/ server, through
 gitlite hooks.
 
+## Archiving a repository
+
+To archive a repository, it must first be deactivated by adding a
+`pre-receive` hook, e.g. in:
+
+    /srv/git.torproject.org/repositories/PROJECT.git/hooks/pre-receive 
+
+The script should display some sort of warning and exit with an error,
+for example:
+
+    #!/bin/sh
+
+    cat <<EOF
+    This repository is deprecated and should not be used anymore.
+
+    See this issue for details:
+
+    https://gitlab.torproject.org/tpo/tpa/team/-/issues/9999999
+    EOF
+
+    exit 1
+
+Then in Gitolite, the repository must be put "in the Attic", using a
+patch that looks something like this:
+
+```
+ repo project/foo
+     RW                                       = anarcat
+-    config gitweb.category                   = Old category
+-project/foo "The Tor Project" = "foo project"
++    config gitweb.category                   = Attic
++project/foo "The Tor Project" = "foo project (deprecated)"
+ 
+ repo project/bar
+     RW                                       = @jenkins-admins
+```
+
+The `description` file in the repository should also be updated
+similarly.
+
+Note that repos can also be migrated (and archived) to GitLab, see
+[the GitLab migration procedure](gitlab/#how-to-migrate-a-git-repository-from-legacy-to-gitlab) for details.
+
 ## Admin details
 
 git-rw runs on `cupani.torproject.org` and runs as the git user. Users in the