A branch name must start with a letter and contain only letters, numbers, and hyphens, up to a maximum of 16 characters. A best practice for the name is to relate it to the planned development work taking place in that branch. For example, when you use a project management tool to organize planned enhancements by identifier, you could base the branch name on that identifier, such as FeatureABC.
Branches must have unique names because they are used system-wide.