(Inspired by this question about Mint. )
You only have to look at Wikipedia to find a long long list of Ubuntu derivatives - should we allow, or even actively encourage, questions regarding these on Ask Ubuntu?
I don't think it will be useful, there's no way to tell if an unofficial derivative has the same setup/versions/packages as an official Ubuntu release, it will just lead to confusion.
Those questions should just go on the Unix and Linux Stack Exchange. There's no need to leave disparaging comments or downvoting the person for posting the wrong thing, just flag it for migration it and put "This should be on unix/linux se" in the text field so a moderator knows it needs to be moved.
Sort of the same reason you wouldn't post about an unofficial derivative on an ubuntu list, or ask for ubuntu support on ask.debian.net, etc.
NOTICE: This post was written long ago in 2011, when the FAQ was where we pointed people for what was or was not on topic. In the intervening four+ years the FAQ for this type of information has been replaced by the Help Center page on "What topics can I ask about here?". The original content of this answer, however, is left here for historical purposes.
If I may at least point at the FAQ... https://askubuntu.com/faq
We welcome questions about:
This is not the right place for:
Given the aforementioned, I believe that Mint and unofficial derivatives (including Crunchbang) should not be supported here, therefore should be marked as offtopic.
And even though this is not IRC, from what I can tell, the official IRC support has its limits. If I may quote the factoids of their bot, ubottu:
There are some Ubuntu derivatives that we cannot provide support for due to repository and software changes. Please consult their websites for more information. Examples: gNewSense (support in #gnewsense), Linux Mint (see !mint), LinuxMCE (support in #linuxmce), CrunchBang (support in #crunchbang), BackTrack (support in #backtrack-linux), Ultimate Edition
Perhaps, due to that, these should not be on-topic as well? (just saying)
My gut feeling is that this is okay, providing the question would also apply on Ubuntu.
So for instance that networking question would apply equally to Ubuntu (as it's a derivative) so would be on-topic, however if the question was about Mint specific applications/community then it would be off-topic.
As of the present moment I find no problem with questions being asked relating to ubuntu derivatives. But come natty narhwhal and the long list of radically new features proposed for it, that would be a problem. Mint is by far the most popular derivative and its developer clement lefevbre has already said NO to UNITY and WAYLAND. I think we would significant differences cropping up in the near future.
I personally find it a bit upsetting that this is even a question! I originally signed up for ask ubuntu after using it as a guest for quite awhile. Why did I finally register? I found the questions & answers to be more relevant than other Ubuntu forums/blogs etc. Now I am considering leaving Ask Ubuntu. I feel that this restriction to discuss only official ubuntu's goes against the core values of the Linux & FOSS ideals. While I do agree that this stack should be used **ONLY for Ubuntu based distros, I do not see why they must only be those ending in -buntu! The idea that a question about other Ubuntu based distros (such as Zorin) is not relevant & is therefore immediately closed to be quite restrictive & yes, a little insulting. While many unofficial Ubuntu based distro have there own set of tweaks & features, at there core they are STLL UBUNTU & in every such case I have seen, funtion closely enough to be TOTALLY relevant here! The freedom ideal that Linux was founded on is essential to me. While rules are a necessity, overly restrictive rules annoy me. Hopefully tese closed attitudes will change on Ask Ubuntu. But until then, I will try to find a more open minded resource!