[xixi77]

After reading their evaluation document, I kinda see the use case. I personally find the mix of letters and numbers a little annoying though.

I think it would be better to use only letters for the first 8 symbols (perhaps after getting rid of some particularly confusing ones like "I"), and only numbers for the rest.

This way you don't need the plus, can use all 10 digits without a chance to confuse them with a letter, remove more potential letter-digit mixups such as 6/G or 7/F in some handwritings, and most importantly make the whole thing a lot easier to say (e.g. over the phone), write (on a phone keyboard you would need only one switch between numeric and alpha layouts, you do want this to be easily texted!), and remember (it's easier to remember a sequence of just letters followed by a sequence of just numbers, imo, even if it's one or two characters longer)

[freyfogle]

In many parts of the world they use different alphabets - Cyrillic, Arabic, etc

[xixi77]

True, and definitely an argument to consider full numeric. I am sure they've thought about that already and decided against though, so I didn't want to go that far.

Also, in practice today there are not many people anywhere in the world who are not at least somewhat familiar with the Latin alphabet to the point they wouldn't be able to recognize/read/write the letters, and (possibly excepting a few old typewriters here and there) people would generally be able to enter letters of standard Latin alphabet into whatever devices they are dealing with.