Thanks to my wife, I know of this very useful package called “showkeys”. Basically, if you put this command
in your preamble and compile the document, the .dvi file will show (in margins) the label that you have affixed to an image, table, or equation. My wife follows with this:
In order to turn the boxes off, either comment out the entire line or include “final” as an option with “notcite” and “notref”.