Vickipedia

PRIVY-SEAL, the seal appended to grants which are afterwards to pass the Great Seal, and to documents of minor importance which do not require the Great Seal. The officer who has the custody of the Privy-seal was at one time called the Keeper, and afterwards the Lord Privy-seal. As early as the reign of Edward III., he was a member of the king’s council, and a responsible minister of the crown. The Lord Privy-seal is now the fifth great officer of state, and has generally a seat in the cabinet. His office is conferred under the Great Seal during pleasure. Since the reign of Henry VIII, the Privy-seal has been the warrant of the legality of grants from the crown, and the authority for the Lord Chancellor to affix the Great Seal. Such grants are styled letters-patent, and the office of the Lord Privy-seal is one of the departments through which they must pass to secure their validity. Until recently, all letters-patent for the grant of appointments to office under the crown, of patents of invention, charters, naturalizations, pensions, creation of honors, pardons, licenses in mortmain, &c., required to pass from the Signet Office to the Privy-seal Office, in the form of Signet bills, verified by (lie Signet Seal and superscription, and the signature of the clerk of the Signet. These Signet hills were the warrant for the Privy-seal; and on the Privy-seal being attached to them, they were forwarded to the Lord Chancellor, by whom the patents were engrossed and completed in the office of the Great Seal. The statute 11 and 12 Vict. c. 83, abolished the Signet Office, and enacted that warrants under their royal sign-manual, prepared by the Attorney-general and Solicitor-general, setting forth the tenor and effect of the letters-patent to be granted, addressed to the Lord Chancellor, and countersigned by one of the principal secretaries of state, should be a sufficient authority for the Privy-seal being affixed; and that the sign-manual so signed, countersigned, and sealed, should be sufficient warrant to the Lord Chancellor to pass letters-patent under the Great Seal. This statute abolished the previously-existing offices of Clerks of the Signet and Clerks of the Privy-seal.

There is a Privy-seal in Scotland, which is used to authenticate royal grants of personal or assignable rights. Eights such as a subject would transmit by assignation, are transmitted by the sovereign under the Privy-seal.