I'm still learning the functionality of Jira,
I was a little shocked to discover the following I've looked on line for any articles to explain this with no luck hence the reason to ask the community.
Whilst writing notes in Jira Service Management from time to time I have flagged the person using the @ (@JoeBloggs) - I have never seen all these Teams before, I've only ever seen the users within my Jira Service Management installation.
Just yesterday before I finished work I went to use this feature in an internal note. to discover groups that I haven't a clue who they are or what they do.


The questions I have are:
Has this always been a feature?
Is this a new feature?
Is it a defect?
Why do I see people / Teams outside of my company?
Why do I see Team from inside my company but they are on another Jira License?
If a User was to Tag one of these Teams by mistake are they able to see this ticket? I expect so
My understanding is that the instant of Jira I used was closed.
Many thanks in advance
Edit:
I've since checked the groups within my Jira Service Management (JSM) and none of them marry to when is shown in the groups displayed.