Since there is often confusion on this site as to which Ubuntu derivatives are actually on topic, why not explicitly list them on the Help page? Instead of:
We welcome questions about:
Using and administering Ubuntu, including official Ubuntu derivatives.
Something like:
We welcome questions about:
Using and administering Ubuntu, including official Ubuntu flavors:
- Edubuntu — Ubuntu for education
- Ubuntu GNOME — Ubuntu with the GNOME desktop environment
- Kubuntu — Ubuntu with the K Desktop environment
- Ubuntu Kylin — Ubuntu localised for China
- Lubuntu — Ubuntu that uses LXDE
- Mythbuntu — Designed for creating a home theatre PC with MythTV
- Ubuntu Studio — Designed for multimedia editing and creation
- Xubuntu — Ubuntu with the XFCE desktop environment
- Ubuntu Touch — Ubuntu for mobile devices
My understanding of the scope of AU is that anything not in that list is off topic. Since that is only 8 items that don't change very often, it shouldn't be too hard to maintain (he said, safe in the knowledge that maintaining it is not his job anyway).
Note: This question was modified following the suggestion made in the comments by @Seth and a discussion we had in chat. See the edit history for the original version.