It's part of the release message. When you get out, your case manager sits down and your Veterans Affairs case manager reminds you that, by the way, you have priority entitlement. Then you get a letter in the mail, and you get one in your VAC inbox online, if you remember your password or banking information to get in. It says the exact same thing: This is what priority means; this is how long you have to activate it; this is what it does.
What it doesn't tell you is that, if you see a job online today, it takes you four to five months to activate it, so that job that closes in two weeks is out of your reach.