I would disagree Mr. Pennick. The American Indoor Air Quality Council owns that designation and has had it for years when referencing their Council-certified Microbial Investigators (or CMIs). Don't take me wrong; I'm not taking sides on who should or shouldn't use it when it comes to describing their credentials. I just think it would be wise for people to find ways to explain their credentials in a credible way where the public becomes educated in the difference; otherwise, for a large portion of the general public, it doesn't mean much more than any other acronym out there.
I've done a lot of research on that subject, even wrote about it on my website (not for home inspection, but the
IAQ industry). I've found (having five industry "certifications" and many more "certificates" - both as defined by the new ANSI/NOCA Standard 1100) that if you don't get out and educate the public in the difference between you and the other guy, making your's something of significance to own, then it may not matter to many who you're certified with and what you're certified in other than you're another "certified" home inspector.
I don't say "let" - I say "make them know the difference", so they
know they want you when they need you!