Rubbings out including black mark over in window recesses (10)

'window recesses' is the definition.
The answer and definition can be both man-made objects as well as being plural nouns.
Perhaps there's an association between them I don't understand?

'rubbings out including black mark over' is the wordplay.
I cannot really understand how this works, but
'black' could be 'b' (abbreviation as in pencil classifications) and 'b' is found in the answer.
'mark' could be 'm' and 'm' is present in the answer.
'over' could be 're' and 're' is located in the answer.
This may be the basis of the clue (or it may be nonsense).

'in' is the link.

Can you help me to learn more?