u/CorgiCadillac

I have a polaris flight coming up and I'm trying to see if I have polaris lounge access, but all of the articles, United's website, and the threads I found via search on this subreddit all just use "basic" vs "standard" without the letter for the fare classes. Can anyone share which letter fare classes are "basic," or if there's a different way for me to tell? Thanks in advance!