Examples of shout outs in other works to the Sharpe series:
In Cornwell's own Gallows Thief, a murder mystery set after Waterloo, the protagonist is an Army veteran whose life was once saved by a Rifle officer and his men.
Cornwell's American Civil War series, The Starbuck Chronicles, includes a French officer traveling with the Confederate Army as an observer. It's clear to readers of the Sharpe series from context that this man is Richard Sharpe's son.
The Fields of Death, part of a "parallel lives" series about Napoleon and Wellington by Simon Scarrow, features a Rifle officer named Richard who unusually carries a rifle like the rankers.
Ads for PC game Empire: Total War featured a very Sean Beanish redcoat in them, which seems odd until one considers that Sharpe dons his signature green jacket much later. (In Napoleon: Total War, as it were.)
The ''Doctor Who'' novelWorld Game features a post-Assaye Wellesley musing on the field commission he's just given to Sergeant Sharpe.
When Boromir cuts his finger on the Shards of Narsil, he announces "Still sharp(e)!" Word of God has it added in for the reference.
Adrian Goldsworthy, the author of a series of books about a British line regiment in the Peninsula, sneaks Sharpe into one: at the battle of Talavera, during the night attack, Goldsworthy's protagonist sees an angry-looking Rifle officer striding past, covered in blood. Sharpe, just after murdering Berry?