The problem is that just about everyone (including Ilford and Kodak) knows it!(posted 8171 days ago)I once found an interesting article on the web about how to do a zone system calibration test for film and prints, written by a well known and well respected author (of course I can't remember his name right now!). He said that if you DIDN'T get about 1/2 the claimed film speed, you should check your test results. If you couldn't do a film test for some reason, rating it at 1/2 the published speed should put you right in the ball park. He was right.
The point of a standard is just that. It should be a standard. If every meter rule you bought was 50cm long, you'd have grounds for complaint, even though you (and everybody else) knew the conversion factor was 2x.
Not that it matters, I'd just like a 100 speed film that didn't need you to try 15 different developers to get 100 speed. In the end it doesn't really matter what's written on the box I guess. Just give me something I can slosh around in a tub of HC-110 that's finer grain than HP5+ and has a true speed no slower than 100 and I'll be happy!