Patent ID: 6967816

Claim:
A recording tape cartridge comprising: a case within which a reel wound with a recording tape is housed; an allowance portion formed as a recess portion in an upper surface of the case, the allowance portion allowing an engaging member disposed at a drive device to advance toward the recess portion and thereby preventing the engaging member from abutting against a front surface of the case in a direction in which the case is inserted when recording and playback of the recording tape cartridge is possible in the drive device; a rear wall formed at the allowance portion, wherein, when the engaging member reaches the rear wall, the rear wall engages and retains the engaging member, whereby the recording tape cartridge does not advance past a predetermined position into the drive device; a position-regulating hole that is formed in a lower surface of the case and into which a positioning member of the drive device is inserted; and a reference surface formed around the position-regulating hole in the lower surface of the case, wherein a case-thickness-direction extended surface of the rear wall is positioned at least in a region of the reference surface.