Thanks to you both for all the information. The riot connection is very interesting.

] JA mentions Capt. Tilney and the 12th in relation to the regiment being called up to quell a supposed riot. Would it be too simplistic to imagine that the 12th's actions in the Nottinghom riot three years before she wrote NA, would still be fresh in JA's mind, and when she needed a regiment to supress a riot, she pulled that one out of her memory?

That's quite possible.

] Too easy? :-/

Perhaps. But stranger things have happened! ;-)

In any case, I think I shall have to leave off trying to make out Captain Tilney's character until I have more from which to judge.