Currently, there are only two off-topic closure reasons besides belonging on a different SE site. They are
Questions on Muslim culture or behaviour unrelated to the teachings of Islam are off-topic here.
Questions on politics are off-topic as they're rarely productive or relevant to the teachings of Islam
I often find a variety of questions that I want to flag as off-topic, but none of the off-topic closure reasons match. For example, I think that questions asking for a practical ruling about specific circumstances should be off-topic is too narrow.
Furthermore, I think that there should be an "Other" option so that the person voting to close can specify why he/she thinks that the question is off topic.