Catchment for in-year admissions?

[Kaida]

Can someone answer a hypothetical question for me please? If you want a school place, with no real sense of urgency, outside of normal admissions times, what are the admissions criteria? Do you need to be within catchment or something to get a place at a school, or could you apply to a more distant one? If they don't have spaces, how do the waiting lists work?
Thanks.

Thanks Tiggytape. So if I go on a waiting list and someone who lives closer later applies for a place they leapfrog over me?

Hang on, so why are houses sold as being "within catchment for xyz school"?

Thank you.