Or, to be a bit more charitable, don’t exaggerate.
Why do I even have to say this? Because of a cover letter I read today, in which an author claimed that their work had been nominated for (among other things) a Nebula Award.
A simple search turned up no record of that author having ever made the Nebula ballot in any category: novel, novella, novelette, or short story.* (Sure, it’s possible that they had written something under a pseudonym that was nominated, but that would have been an important detail to mention.)
Pro tip: Having someone tell you that they nominated your work for a Nebula does not equate to being a Nebula nominee. That title applies only to work that made the final ballot.
Pro tip the second: The person who’s reading your cover letter probably has a computer and knows how to do a search, so your lie — or your exaggeration — is likely to be discovered. And when it turns out that you weren’t actually on the ballot for that thing you claimed, your credibility and reputation suffer.
You’re better off not including a cover letter at all than to send one that’s so demonstrably bad.
___
*Or even script, back when that was a category.
by 
Or their work was nominated by one or more members of the SFWA but not by enough to make the final ballot. The SFWA is trying to move the goalposts on the English language.
If your work received a nomination by an eligible member of the SFWA, it was nominated. Shame on you for buying into the SFWA BS and assuming the writer is lying.
Classy e-mail address, ye who hides behind anonymity. Shame on me? Shame on you for your vulgarity (which, it appears, was reserved to me alone since it was part of the presumably fake e-mail address) and cowardice. How about state your name, at least?
No one is moving any goalposts. A Nebula nominee, as with an Academy Award or Grammy or Prometheus nominee, or for that matter a political nominee, is the one who has made it through the initial gauntlet in order to appear on the ballot.
As for my assuming the writer is lying, note that I allowed in the very first line of the text for the possibility that the writer was merely exaggerating. That’s not much better, though.
But, hey, congratulations on having someone suggest your work for a Nebula, whoever you are.
G