This page is an entry in the Key.
“IC” is an abbreviation for “inapparent circumstances.”
Photographs made depicting inapparent circumstances — including “photos that do not depict what they appear to depict” — can qualify for the “Guaranteed TCQ” label if the photographer ensures that viewers will not be deceived by the photo.
An “IC alert” is how TCQ photographers alert viewers to “inapparent circumstances” that are potentially deceptive, as per Q8.
Technically speaking every photo every made has innumerable “inapparent circumstances” behind it, from the photographer’s upbringing and worldview to the evolution of the scene being photographed.
But TCQ photographers need only concern themselves with “inapparent circumstances that viewers would want to know about.”.