Letters patent, is derived from Latin word 'literae patentes.' The letters patent are so called because 'they are open letters; they are not sealed up, but exposed to view, with the great seal pendant at the bottom; and are usually directed or addressed by the king to all his subjects at large. And therein they differ from certain other letter of the king, sealed also with the great seal, but directed to particular persons, and for particular purposes, which therefore, not being proper for public inspection, are closed up and sealed on the outside, and are thereupon called writs close, literae clause, and are recorded in the close-rolls, in the same manner as the others are in the patent-rolls.' (See Blackstones Commentaries on the Laws of England, volume II, pages 284-285), P.V. Hemlatha v. K.P.M. Saheeda, AIR 2002 SC 2445 (2457): (2002) 5 SCC 548. [Civil Procedure Code, s. 98(3)]
Means letters patent are open letters; they are not sealed up, but exposed to view, with the great seal pendant at the bottom; and are usually directed or addressed by the king to all his subjects at large. And therein they differ from certain other letters of the King, Sealed also with the great seal, but directed to particular persons, and for particular purposes, which therefore, not being proper for public inspection, are closed up and sealed on the outside, and are thereupon called write close, literal clausal, and are recorded in the close-rolls, in the same manner as the others are in the patent-rolls, Blackston's Commentaries on the Laws of England, Vol. II, pp. 284-85.