
Will someone tell an ignorant physicist where the term "Level 5" comes
from? It sounds like the RISKS Digest  equivalent of Large, Extra
Large, Jumbo... Or maybe it's like "Defcon 5..."

I gather it means that Shuttle software was developed with extreme
care to have reliablility and safety, and almost everything else in
the computing world is Level 1, or cheesy dime-store software.  Not
surprising.  But who is it that invents this standard, and how come
everyone but me seems to be familiar with it?