I imagine there's relatives like the programmer beard, but googling "UNIX
beard" returns some examples where it seems to be a thing.
http://www.usenix.org.uk/content/unix_beards.html
https://www.urbandictionary.com/define.php?term=Unix%20beard
https://www.reddit.com/r/linux/comments/4nt38v/how_many_of_you_have_a_unix_beard/
https://www.atlasobscura.com/articles/why-do-hackers-love-beards-so-much
subtitle:
" Decoding the “Unix beard” at this year’s DefCon.
https://pthree.org/2009/11/01/get-your-unix-beard-on/

 Tyler


On Fri, Dec 18, 2020 at 3:56 PM Noel Chiappa <jnc@mercury.lcs.mit.edu>
wrote:

>     > From: Tyler Adams
>
>     > We all know and love the UNIX beard, but I can't find anything on how
>     > the beards started other than an old photo of Ken and Dennis
>
> I'm not sure the term is Unix-specific. At a fairly early stage, people who
> worked on the ARPANET/Internet (when PDP-10's were still the 'usual' host,
> and
> Unix systems were just starting to beceome common) were jokingly known as
> 'network grey-beards': the prototypical one being Jon Postel. (Vint Verf's
> beard was too tidy to qualify, IIRC!)
>
>       Noel
>