Managing multiple git configurations to separate work/personal identities and other configuration differences.

.gitconfig

# file: ~/.gitconfig
# my name is the same in real life and at work.
[user]
	name = "Sean O'Donnell"

# All repos/subdirectories in ~/projects/work/ shall respect my work email address/config.
[includeIf "gitdir:~/projects/work/"]
        path = ~/projects/work/.gitconfig

# All repos/subdirectories in ~/projects/personal/ shall respect my personal email address/config.
[includeIf "gitdir:~/projects/personal/"]
        path = ~/projects/personal/.gitconfig

.gitconfig.personal

# file: ~/projects/personal/.gitconfig
# my personal email address.
[user]
	email = "myusername@my.personal.domain.com"

.gitconfig.work

# file: ~/projects/work/.gitconfig
# my work email address.
[user]
	email = "myusername@my.employer.domain.com"