I'm currently on a webcast with one of our vendors who is explaining that

"any users of their _____ Ver.9 or Ver. 10 software who wish to upgrade to their new 4.1 software, must first upgrade to Ver. 4.0.

Additional conversation:
Us: Why did the numbering go down instead of up?
THEM: Because we added the Acronym _ _ _ in front of the number to signify the new way we sell the features.
Us: Well, wouldn't that make it version 1.0?
THEM: No this product has been around a long time so it's not a version 1.
Us: So again, why go backwards.
THEM: {pause}
THEM: OK, our marketing dept. tells us that the name 4.0 will sell better than 11.0, OK!!! Can we move on?

sigh.........

Lovely. Any number of products out there like this. It just makes life confusing as all get-out.

Yeah, version numbering decisions are a nightmare. I have never built any products that, apart from the first versions done without marketting dept, did not require weeks and weeks of meetings and debate to pick the version number that sends "the right message" (i.e. not a buggy first version, not too high as to indicate it is old technology...)

What I love are software products that have been in existence for many years, and still haven't hit v1.0...

For example, MAME software (Multiple Arcade Machine Emulator) has been around since 1997 and is currently on version 0.136... If that wasn't bad enough, it has gone, in order, through these version numbers.
0.1
0.4
0.12
0.13
0.18
0.19
0.23
0.26
0.26.1
0.27
0.27
0.28

Ok, that was all in 1997. Some other versions of note are ones like:
0.34b1
0.34b2
0.34b4 (there was no 0.34b3 I guess)
0.36rc1
0.106u1


So on and so forth... What a mess.

Ah, open sores.

I work for a clothing manufacturer. I alway get a kick out of the color names that our marketing dept. comes up with. Lots of food references
Tangy Peach
Pumpkin
Taffy Pink
Celery......

Remember some of the names for colours Chrysler/Dodge used to/are using?

Sublime
Top Banana
Panther Pink
Go Mango
Moulin Rouge
Furious Fuscia

I had to do a double take on the thread title. At first I thought I read Marketing Meth.