A commit messages consists of three distinct parts separated by a blank line: the title, an optional body and an optional footer. The layout looks like this:
The title consists of the type of the message and subject.
The type is contained within the title and can be one of these types:
Subjects should be no greater than 50 characters, should begin with a capital letter and do not end with a period.
Use an imperative tone to describe what a commit does, rather than what it did. For example, use change; not changed or changes.
Not all commits are complex enough to warrant a body, therefore it is optional and only used when a commit requires a bit of explanation and context. Use the body to explain the what and why of a commit, not the how.
When writing a body, the blank line between the title and the body is required and you should limit the length of each line to no more than 72 characters.
The footer is optional and is used to reference issue tracker IDs.