27. Contracts required to be in writing.

A contract for the sale or other disposition1 of an interest in land2 can only be made in writing and only by incorporating all the terms3 which the parties have expressly agreed in one document or, where contracts are exchanged, in each document4. The terms may be incorporated in a document either by being set out in it or by reference to some other document5. The document incorporating the terms or, where contracts are exchanged, one of the documents incorporating them (but not necessarily the same one), must be signed by or on behalf of each party to the