Notice that in the bad old days part numbers could be
decifered to tell
you what the hell they actually did?
You do not use tubes much, do you?
Most of the old numbering systems had so many special cases, mistakes
in registration, and other weirdness that the systems basically could
not be trusted.
Everyone was to blame - the American RMA, the various British systems
(the worst offenders), the Continental system, the German systems, the
Japanese systems...
The best system turned out to be the 5500 series non-system in use
from roughly 1950 to 1970.
--
Will