The important thing as a PR is that the admins give some feedback on their experience with you in the server. We go on that feedback when we make decisions about your recruitment. You are encouraged to do what you can to ensure you get some racing feedback reports posted.
If you want to put on the PR tags, that's fine. I would definitely suggest telling the admins that you're a PR as well. If they say "thanks" or "good luck" or "I could tell from your tags :P", then you know they saw it and see you as a PR. Of course, the best thing to do for this important feedback is to do well in the servers - focus on racing, have fun, follow rules, etc.
I like when PRs tell me they're a PR because it's more sociable than throwing some letters on their name and then not talking to me at all. Personally, I don't care for the PR tags, I'd rather see interaction, and I'm not the only one who thinks this way. Other admins look for PR tags and keep track of them, and are glad PRs use the PR tags. As you can see, if you do one or the other or both you can't go wrong.
Technically, you don't have to tell us anything and you don't have to use the tags. You can easily get yourself noticed by your actions and your attitude. Anything extra is just that - extra. Do it if you want, it will be mentioned, but we're looking for YOU. If you don't think you're standing out as much as you'd like, wave some PR flags.
And good luck RyMx!