Geting rid of items?

Is it possible to have the player collect for example the four key's but then later, take those key's away?

Copy-pasta on a key removal square in the ini:

[x1000y1000]
ShiftVisible(A)=False
ShiftTouch(A)=True
ShiftFlagOff(A)=Power#

With a shift make a flag take away the keys.

Thank you !! =-D