The sponsor must have the ability to explicitly state these two aspects about acceptance criteria:
1) Whether solution must be implemented in the main project's source repository, or if a forked repository is ok.
By checking that, the sponsor is sponsoring the only the original project, not some fork of it
2) Whether solution must be available on a release version.
By checking that, the sponsor is saying: “Just commiting is not enough. Solution must be available in a released, easily installable version”
Like this sponsor did with the textarea field: http://www.freedomsponsors.com/core/offer/1/ui-delete-multiple-styles-at-once
DONE / Accepting payments