The operation of any covenant implied in an instrument by virtue of this Part may be limited or extended by a term of that instrument.
Sections 81 and 83 of the Law of Property Act 1925 (effect of covenant with two or more jointly; construction of implied covenants) apply to a covenant implied by virtue of this Part as they apply to a covenant implied by virtue of that Act.
Where in an instrument effecting or purporting to effect a disposition of property a person is expressed to direct the disposition, this Part applies to him as if he were the person making the disposition.
This Part has effect—
where "gyda gwarant teitl llawn" is used instead of "with full title guarantee", and
where "gyda gwarant teitl cyfyngedig" is used instead of "with limited title guarantee",
as it has effect where the English words are used.