I have a Silva 4/54 compass with a rotating bezel. On the inside of the bezel it is marked up to 360 degrees, no problem there. On the top of the bezel it is numbered 2,4,6 etc up to 62 and then North at 64. East = 16, South=32 and West= 48. I am sure that this is going to be something really obvious and that I will kick myself but at the moment I have no idea at all what these numbers indicate.
I think it's the declination (sp?) adjustment, as magnetic north is several hundred miles away from true north proper maps have a declination diagram on them which you use along with the scale on the compass to compensate for the difference in true and magnetic north.
They are simply the points of the compass as in 'periscope 2 points off the starboard bow Captain' and 'steer north-north-east a half east Mr. Christian'. There are also 32 point compasses.