The naming convention, I propose, have four sections:

1. Story Type:
   • add == Add Feature
   • fix == Fix, Hotfix, Bug, …
   • clean == Cleanup, Chore, …
   • modify  == Modify existing functionality
2. Short Summary: 2-3 words about what the branch contains
3. Tracker ID (Planio, GitHub, … )

First section is group and is separated with dash. 2nd and 3rd sections are separated with hyphens. The end result looks like this:

{story type}/{2-3 word summary}-{tracker id}