Basement Egress Window Need Be a Window?

I searched some online and couldn't find an answer. Egress codes always talk about a "window", but is there any reason it can't be a small door or hatch? Given that all the size & height requirements are met, I'm not sure why it wouldn't be acceptable, but maybe the code expects that an escaping person might need the outdoor light to find the window in an emergency.



I'm considering installing an egress window under a porch and since it wouldn't really get light anyways, I figure I might make it a little door. I'm aware of the need to have a 3ft high clear patch out from under the porch.



Thanks!

Basement Egress Window Need Be a Window?