Short Pozidrive (not Phillips) head screw used to retain the front drum and standard rear drum to the drive flange or rear hub. Also for 997/998 disc brakes. 0.30" thread length. See larger photo for comparison with similar screws.
Use HDWS293 for rear drums with 0.75" built-in spacer.
A set of correctly-sized Pozidrive screw drivers is handy for working on British cars of this vintage, and helps prevent damage to the screw slot.