What exactly do you do with your PHN license?

I recently got my PHN license number and certificate but i'm not exactly sure what you use it for. I just applied and paid for it because I met all the criteria to have but I don't know what its used for. I just got it to put some extra letters behind my name to be honest lol. So if anyone can tell me what its used for and any benefits of having it, id appreciate it, thanks.
For those who don't know, PHN=Public Health Nursing Certificate, at least in California.Having the PHN makes you eligible or a stronger candidate for a lot of community/public health jobs. In the state of California, a PHN is required for most of these positions anyway.