Searching, I found the topic "ICG and ANACS vs. PCGS and NGC", and say someone complain that some of the ICG coins he purchased, when regraded by NGC, came back with the dreaded "details" designation due to the fact that they had been cleaned, and one ICG MS61 came back as NGC XF45.
I couldn't find anything under "IGC", did you mean "ICG"?
-- Tom