Domain language for the jquery-form/form library and how it is released.
main: The single long-lived integration branch; all active development targets it. Avoid: master, develop, next (as standing integration branches), trunk (as a branch name)
v4 line: The 4.x compatibility release line (legacy jQuery and shim support retained). After 5.0 ships, patches still belong to this line. Avoid: old major, legacy branch (when meaning the release line rather than a git ref)