Excellent post tacit.

Originally Posted By: tacit
So if you rename a DNG and its icon suddenly disappears,

Unfortunately, even that tiny amount of information hasn't been afforded us as yet (and we're on page 3 now). Despite my specific query for that exact detail, we still aren't sure if that was the sequence of events [or if perhaps there was never any icon there in the first place.]

Sounds as if that .dng format is intended for professionals, and perhaps others sorts of users would be better off converting to friendlier formats early on in their "workflow".