Where does the variable GIT_HOSTING comes?

Hi all,

On Ubuntu 20.04, see my following relevant git variables settings:

$ env |grep GIT
GIT_SSL_NO_VERIFY=1
GIT_HOSTING=git@git.domain.com
GIT_DISCOVERY_ACROSS_FILESYSTEM=true

I don't set the `GIT_HOSTING' variable at all. Then where does it come
from and what's the function of it?

Regards
-- 
Assoc. Prof. Hongyi Zhao [off-list ref]
Theory and Simulation of Materials
Hebei Vocational University of Technology and Engineering
NO. 552 North Gangtie Road, Xingtai, China