OK guys; I've found what I was looking for (the basics, anyway).

It seems that a CIVAB code is an "eight-character string" that identifies a model of biomedical equipment. The code comprises:-

1) Equipment class (3 chars)
2) Manufacturer (3 chars)
3) Model (2 chars)

For example:- DEF HPI 20 indicates "Defibrillator, Hewlett-Packard, 43120-A"

And yes, the Si3C system does (or certainly did) use such codes as these. smile

But what is not clear is that when the complete CIVAD code needs to be quoted, is it given as:-

1) DEF HPI 20 (ie, with spaces)
2) DEF-HPI-20 (10 chars)
3) DEFHPI20 (and parsed by the system)