.ICC vs. .ICM?

[Bodog]

Can someone tell me the difference? I notice that In some instances I have both files installed for the same profile. Example: Adobe RGB(1998).icm and Adobe RGB(1998).icc. Which should I be using? Is there a difference? Thanks...
(edit) looks like the forum interprets and eight)period as a smiley.

[poke]

Extract from http://www.devarticles.com/c/a/Photoshop/The-Critically-Important-Color-and-Gamma-Calibration-Article/2/

Because the Windows operating system had already assigned the ICC suffix to another system component, Windows refers to ICC profiles as ICM. The suffixes ICC and ICM are interchangeable in the language of CMS.

[Bodog]

Thanks, Poke, looks like there is no difference. Seems strange both would be installed though...