Czech to English Tech/Engineering Mechanics / Mech Engineering abbreviation

Context: a test report for a structural strength test, originally written in Czech and translated into German, which now has to be translated into English.
The translator apparently overlooked the abbreviation '?.' (that's supposed to be a c with caron diacritical, in case it doesn't get encoded properly), and the client can't be bothered to answer questions. From the context, I imagine
it's an abbreviation for 'number', 'item number', or something like that.

Specific context:

Cables ?. I, II, III, IV, V, VI, 1, 2, 7, 1sv, 2sv
Load cell U1 5 t ?. B32301, B32302, B32303, B32304
Displacement transducer type W20 ?. 39624, 39631, 39626, 39629

TIA