A two-parent, no-fast-forward merge. The source branch is unchanged. This is the default behavior.
Rebase the source branch on top of the target branch HEAD commit, and fast-forward the target branch. The source branch is updated during the rebase operation.
Rebase the source branch on top of the target branch HEAD commit, and create a two-parent, no-fast-forward merge. The source branch is updated during the rebase operation.
Put all changes from the pull request into a single-parent commit.
Enumeration of possible merge strategies which can be used to complete a pull request.