What’s That Alert or Question Mark Icon in InDesign?
I occasionally see question marks or yellow warning triangles with an exclamation point in them. I can't figure out what they are trying to tell me.
InDesign has various alert icons scattered throughout the program, so I'm not sure exactly which you're talking about. I'll cover all the ones I can think of.
The main place you'll see both yellow triangles and red question marks is the Links panel. Red means "missing" (InDesign can't find this file on disk) and yellow means "modified" (the file changed since you imported it). You can use the Relink and the Update buttons to fix these solutions.
Colors and Swatches
The yellow triangle with an exclamation point that sometimes appears in the Color panel or the New Swatches (or Swatch Options) dialog box means the color you picked cannot be reproduced in the current CMYK color space. If you click on the little swatch next to the icon, InDesign will snap the current color to the nearest CMYK-valid equivalent.
Hyperlinks and Cross-References
The Hyperlinks panel can also show some alerts, including the "Hey, something is wrong with this hyperlink" icon (red flag), the "Hey, someone deleted the text that this cross reference is pointing to" icon (red flag), and the "Watch out, the text or page number of this cross reference needs updating" icon (yellow triangle). The latter two are CS4 only, of course (cross-references are new in CS4).
I can't think of any other flags or alert icons in InDesign, though I'm sure some eagle-eyed reader will surprise us with another one or two. Any takers?