Description vs. Comment vs. ???

[frankiesatin]

Is there a difference between "description" and "comment"? And which one is more likely to show up when viewing in other programs? Does one of them correspond to "caption" in other programs?

EDIT: I see there is also a "caption" field under IPTC. So now I'm thoroughly confused. Which of these is the most universal, and most likely to be picked up in, say, Facebook, or Photobucket?

[xnview]

Description is saved in an external file descript.ion
Comment is embedded in the file (PNG & JPEG)
IPTC is perhaps more universal

[Silversleeves]

I'd also suggest clicking the checkbox in "Edit IPTC Data" that's marked Update or create XMP. There are a few image viewing, editing and cataloging applications, many of them commercial, that will read in an XMP Description -- more or less the same thing as an IPTC Caption -- sooner than they will the other two tags. PhaseOne Media Pro (formerly MS Expression Media 2, formerly iView Media Pro) is one example of such an application. This last completely ignores JPEG Comment and descript.ion information in files, as do many freeware and open source image apps in Linux, I've noticed.

Just my 2c.

BZT