document how to delete a tag

docs/koji/deletetag.md

+# Deleting a tag in koji
+
+Eventually, SNow tickets will come our way regarding the need of deleting an obsolete tag in koji (e.g. [RQF1766211](https://cern.service-now.com/service-portal?id=ticket&table=u_request_fulfillment&n=RQF1766211).
+
+To accomplish that mission, start by cloning the [lxdist-build](https://gitlab.cern.ch/linuxsupport/lxdist-build) repo.
+
+## Remove the tag from the repository
+In the `bin/tags` directory, find the file which documents creating the tag. Remove that file with git rm <filename> and commit that change with reference to the SNOW ticket asking for the removal.
+Push and create a merge request for the team to review
+
+## Update the checkout on lxsoftadm01
+
+Please update the clone of this repo on lxsoftadm01:
+
+```bash
+~ > ssh build@lxsoftadm01
+[build@lxsoftadm01] cd bin
+[build@lxsoftadm01] git pull
+```
+## Untag packages
+If there are any packages using these tags, it is better to untag them before removing the tag from KOJI.
+
+## Remove the tag from koji
+From lxsoftadm01 remove all related tags from koji
+```bash
+~ > ssh build@lxsoftadm01
+koji remove-tag $DIST-testing
+koji remove-tag $DIST-build
+koji remove-tag $DIST-qa
+koji remove-tag $DIST-stable
+
+```
+where ```$DIST``` is to be replaced by the tag to be removed.
+
+

mkdocs.yml

@@ -45,6 +45,7 @@ nav:
         - 'Adding users to koji': koji/addingusers.md
         - 'Untagging policy': koji/untagging.md
         - 'Creating a tag': koji/addnewtag.md
+        - 'Deleting a tag': koji/deletetag.md
         - 'Upgrading koji': koji/upgrading.md
         - 'Bootstrapping a new distro': koji/bootstrapping.md
         - 'Troubleshooting': koji/troubleshooting.md