All users at your site are using the Bash shell. You want to set a variable that will apply to every user and always have the same value. Which files would you place this variable in:

I assume you are on a single host.

To modify the. bashrc for all NEW users, you can edit/modify (with su privilege) the file

/etc/skel/. bashrc

save the file before creating new users.

Be sure to know what you're doing, and test the file before you use it host-wide.

For existing users, you can have them do the modifications/additions individually in case they have already modified their own version.