2.
The concordance between US classes and IPC is, in my experience, highly
unreliable. The two systems try to classify in quite different ways, and
you will find that sometimes there is 1 US class corresponding to a range of
IPCs, sometimes it works the other way - depends upon the area of
technology. The US has in its favour a more rapid updating system. I have
in the past used CLAIMS or similar to identify relevant US cases using US
classes, then crossed the results to Derwent and looked at the IPC applied
to other family members - assuming that there are any. This can be quite
helpful.
I agree with the person who spoke about IPC:CLASS - we have the provisional
Windows edition v.2.1 and I like it. I always tend to use the German
"Stichwort" catchword index first, as it is much better at subject coverage.
Searching the actual IPC definitions, at least in the chemical area, is a
waste of time.
Hope this helps
Stephen Adams
Zeneca Agrochemicals
stephen.s.r.adams@gbjha.zeneca.com