The term was originally used in the Writings of the Bahá'í Faith to refer to someone who was a Bahá'í and who then chose to oppose Bahá'u'lláh. After the passing of Baha'u'llah, it became opposition to the appointed Interpreter of the Faith, Abdul-Baha. In Abdul-Baha's Will and Testament He appointed Shoghi Effendi as the Guardian of the Baha'i Faith, and defined again in the same manner opposition to the Guardians as Covenant-Breaking. Abdul-Baha advised all Bahá'ís to shun anyone opposing the Guardianship.
Bahá'ís under the Hands of the Cause defined opposition to them as Covenant-Breaking, and when they elected a Universal House of Justice opposition to it as well.
Hence the Baha'is under the Hands, and now under their Universal House of Justice, have declared all members of the Orthodox Bahai Faith as Covenant-Breakers. Members of the Orthodox Bahá'í Faith view the followers of the Bahá'í Faith as misled but not Covenant Breakers, though the leadership of the Hands, and later the Universal House of Justice are viewed as having broken the Covenant.