Others require the written form and others require a public form. A public form requires that the contract be published by a notary and in the case of immovable property, registered in the public registrar.
Wengine wanahitaji mfumo wa maandishi na wengine zinahitaji aina ya umma. fomu ya umma inahitaji kwamba mkataba kuchapishwa na mthibitishaji na katika kesi ya mali zisizohamishika, kusajiliwa katika msajili wa umma.