These in Scotland are not sealed, but must be signed on every page by the parties, and on the last page the signatures must be attested by those of two male witnesses, whose names and designations, together with the name and designation of the person who wrote the deed, must be stated in the "testing clause" (attestation). In the same place must be stated the number of pages of which the deed consists, and the date when and place where executed. When the necessary formalities above mentioned are complied with, the deed is said to be probative, i.e., it
proves itself, unless an action is brought to set it aside on some legal ground. Holograph deeds, i.e., those written wholly by the hand of the grantor, are also privileged to the extent of being admitted without the attestation of witnesses, except as to the date of execution, which, when material, must be proved otherwise. A deed cannot be subscribed by a mark ; but when the party cannot write, it mu.st be subscribed for him in his presence by two notaries, and before four witnesses. There is no distinction resembling that between deeds poll and indentures, but a deed poll is sometimes called a unilateral deed. (See Erasures.)

Source: Kinnear, Digest of House of Lords cases (1865), pg. 353.