It is unclear to what extent Carl Barks added Remarques* to his autographed lithographs. Chances are that he did it very rarely, because they are not commonly known. Still, when he readied the 300 lithographs for his painting 40-78 King Beowulf (see more HERE), he apparently accepted orders for adding remarques to about 150 copies. His ledger is filled with names for many different recipients, several of which seem to have been given tailor-made remarques. Barks' sales manager at the time, Bruce Hamilton, also received copies to be sold at various comic book conventions.
The remarque examples rendered on this page (they are from 1-80 Xerxes and the Harem) in no special order were, of course, very small (Barks sketched about 10 on a single sheet of paper and they were all made as funny cartoons in pseudo-historic harem-like settings). This fact combined with the fact that they were all hastily jotted down idea sketches, also mean that they are difficult to reproduce in a satisfactory manner. But you get a valuable insight in an otherwise unknown area of Barks' activities...

* A remarque is a small, personalised drawing or symbol that an artist may add to a print near his signature. The presence of a remarque increases the print's value especially to collectors.