Distinguishing Thomson from Thompson?

Are there any ways to distinguish which Thom(p)son is which?

The only way to tell them apart I can think of is that Thomson's moustache turns up slightly at the ends, whilst Thompson's doesn't (hope I've got that the right way round!) In all other respects, apart from the "p", they're identical - I think there may be a thread around here somewhere pondering whether they're real twins or not...

Here's a page I put together to distinguish the Thom(p)sons visually: http://tintin.eugraph.com/tqsect/feature/tvst/index.html

Is there really a need to distinguish them? I mean they are very similar people, and I doubt if anyone can spot a difference in their actions.

Sure they were meant to be the "same", although I wonder if Hergé did that just for comedy reasons, or is it a joke about the police force/ army/ similar organizations which demand a strict code of conduct?

Um, I know this is an English forum, but I thought you guys might find this cute:

When I was in grade 9, my French teacher told us that Dupond (with a d) has a moustache that's droit (straight) and Dupont (with a t) has a mustache that tourne (turns).

I check this out and whenever each has been identified with the proper last letter, his mustache has been in order!

Moderator Note: Top marks to teacher! The audio-visual guide to the Hergé Museum plays a small animation that makes exactly this point!

The Tintinologist Team (with a "t" as in "bristle")