When we close or flag a question as off-topic, we have an option called belongs to meta.physics.SE. We're also receiving questions that belong to Math.SE or Electronics.SE most of the time. So, it'd be easy for migration if there is a choice for belongs to Math.SE and belongs to Electronics.SE. Well, other sites do have that option.

For instance, we can take Android.SE. It's having a choice for belongs to SO. I think superuser is also having such an option.

• This we can probably have. We are allowed up to five migration targets. I'd like to see Scientific Computation as well, but I don't think they put beta sites on the list. – dmckee --- ex-moderator kitten Mar 26 '13 at 14:39
• The five migration targets should be chosen by experienced volume of migrated questions until now. The last 90 days indicates (in decending order): 1. Math, 2. SciComp, 3. Chem, 4. EE, 5. Bio. – Qmechanic Jul 1 '13 at 13:43