German to English Medical Medical: Pharmaceuticals Pack sizes

This is from an official form dated 1968, for permission to allow PROGYNOVA to be sold in Germany.

under the item "Packungsgrößen", one entry is:

"OP mit 21 Dragees"

I did some research and conclude that "OP" here means "Originalpackung" and is equivalent to "N1".

But below that the entry is:

"UM mit 21 Dragees (Kalenderpackung)"

I cannot find anything to determine what "UM" may stand for or mean.

Appreciate any help. This dates from 1968 so may be obsolete, perhaps nowadays called N2 or N3,

Thanks,

Stephen