A little-known feature was added in the 3.x develop branch of NodeBB, custom fields. It was an often-asked-for feature that had a couple of plugins built to accommodate, but @baris decided to make this part of NodeBB core.
I will let him do a more detailed write-up on the NodeBB side, but suffice to say, those custom fields will now federate out with your profile:
Likewise, custom fields as defined by remote users will be saved and displayed in NodeBB in metadata boxes just like those defined in NodeBB.
In NodeBB, administrators are able to globally specify a set of fields that individual users can change/set.