~/.gitconfig file and please don't confuse it with Gitlab, Github nor other user accounts). Whatever you'll commit the user data written in ~/.gitconfig it'll appear in your git logs.
Usually, employers don't care, although some of them require a specific company credential while communicating with their repositories, so I figured out, that I can have multiple local git users in the same file, however activate only single one when I need it.
# ~/.gitconfig
[include]
# For user, email, ect.
; path = ~/.gitconfig.local # colon make this configuration inactive
path = ~/.gitconfig.local_work# Sample of private configuration
# ~/.gitconfig.local
[user]
name = John Doe
email = firstname.lastname@example.com
# Public work configuration
# ~/.gitconfig.local_work
[user]
name = Maciej Sypień
email = firstname.lastname@workmail.com~/.gitconfig.local_<company>. So I can use it for my personal accounts or for some specific credentials required by employers - the field of usage is almost endless.~/.gitconfig.local and uncomment (enable) specific configuration for work ~/.gitconfig.local_work.pre-commit hook script that is available in any Git version higher than v1.8.4.git commit -m "whatever") then Git runs its hooks (if they're defined) and program checks what e-mail addresses are valid for this repository and allow or reject users with small information, that only a specific group of e-mails are allowed to commit in this repository..git/hooks/pre-commit into your Git repository and don't forget to make the file executable via chmod +x .git/hooks/pre-commit. In the final step, modify the list of e-mail addresses and that's it."How to disable some not authorized git users to commit in selected local repositories".