What does # next to username mean?

I noticed that at least one user has “#” next to his/her name.  What does it mean?

I have no idea

It’s a flair I think 

It’s a flair, # means checkmate.

No.  There is a “#” next to username.  For example :

My username : iceman073.  Then, you would see country flag then membership icon if any then #.  I saw at least one unsermae with “#” next to it.  So, I wonder what it means.  I hope that my explanation is more clear.  

Let me look for the username and screen shot it.

I think it's a flair.

See “#” next to Rixy99 and flag.  The username is on top left area above the chessboard.  I just want to understand what it means.

Yes, that's a flair. Mine is a donkey. His is a #.

Agreed.

I have a new flair!  Rook appears next to my username and flag.  I’m glad I asked!

any free membership gift ? lol

chess