In my contacts, there is a # Hashtag after A-Z sorting

In my contacts/address book, there is a # Hashtag after A-Z sorting. Under the hashtag is a few numbers. I'm trying to guess why this is. I just had reset my phone/got a new one about a month ago, but just noticed this. I'm wondering if they're recent numbers that I have called, or just phone numbers that had gotten saved to my cloud from a little while ago.

I tried asking my brothers girlfriend if she knew/had the same thing. She scrolled through her contacts and found a phone number there and had no idea who it was.. She tried adding another phone number without the contacts name, and the number got saved to the hashtag area.. but I don't think this is my case.

Are these recent phone calls/texts, or back ups? Or what?! Helpppp! 😀

Thank you!!!! <3