Hmmm, to make matters more confusing, it seems Microsoft themselves are not consistent in deploying these guidelines:

http://www.microsoft.com/typography/otspec140/recom.htm
http://www.microsoft.com/typography/OpenType%20Dev/devanagari/intro.mspx
&c.

I think it’s probably best to avoid the hyphenates. It reads like marketing-speak or technical pedantry, neither of which is especially inviting to end users, who probably understand that OpenType-formatted fonts, Opentype-based fonts, and OpenType fonts are all the same thing. Keeping a human face on fonts is important if we want designers to think of type designers as people trying to earn a living and not faceless corporations raking in money from stockpiles of computer-generated IP.

Si Daniels, bless his heart, tried to remind people of these guidelines in the first few years, but I'm sure he's given up now. As James says, it's really not important unless there's a potential for misunderstanding. Another example: Apple refers to the iPhone like it's a person: "don't eat iPhone" but even the most Apple-savvy journalists say "the iPhone". No big whoop.

But you're at Adobe now, Paul! What do their guidelines say?

I do however cringe whenever I see Opentype or Open Type.

The guidelines really say to use a hyphen like that? Adobe's lawyers would have a cow every time somebody tried to take a trademark and turn it into a hyphenated term like that.

Huh.

T