What does - P 5 at the end of the track titles mean?

Maybe this is a stupid question, but I don't know why they write this. What does - P 5 at the end of the track titles mean?

I don't think it's a stupid question at all. Now, I'm speculating here, but it could be that people who upload to multiple sites then have a way of tracking where they've made a specific sale if they spot it "in the wild", so to speak, and the track has been listed with its full name. Could also be SEO, so that it's more likely to show up in Google or something when people search for Pond5? Would be curious to hear from someone who has some of these tracks uploaded.

As far as I understand, P5 is a unique track that is only available on Pond5?

It means that the contributor has signed up for Pond5 Publishing:

https://explore.pond5.com/publishing/

Thank you very much for the information.