If you commit something to a package in LHCb you should (normally) add the tag in the LHCb tag collector (https://lhcb-tag-collector.web.cern.ch/lhcb-tag-collector/index.html). To add it:

1. Login (top right)
2. Go to New Package Revision
3. Select the package by typing in the name
4. Click in the table on “More”
5. Select the revision
6. Change (if necessary) the message
7. And hit “Add”