Look on the back of the tape (the edge on the opposite side to the flap)on the left hand side there will be a square hole,if there is then the protection tab has been removed that means that the tape can not be accidently copied over,if you want to record over the tape you stick a piece of selotape over the hole and you can record over it again.If it has a piece of plastic covering the hole you can record over the tape,if you want to protect it from accidental erasure you snap the piece of plastic off.
Rich, December 2010