Pokership or Parkership

In Collins' *Peerage*, vol. iv. p. 242., 5th edition, 1779, we are told that Sir Robert Harley, of Wigmore Castle, in 1604, was made Forester of Boringwood, alias Bringwood Forest, in com. Hereford, with the *office of the *Pokership*, and custody of the forest or chase of Prestwood for life. The same word occurs in the edition (the 3rd) of 1741, and in that edited by Sir Egerton Brydges in 1812 (vol. iv. p. 57.). If *Pokership* be not a misprint or misreading of the original authority, viz. Pat. 2. Jac. I. p. 21., for *Parkership*, can any of your readers tell me the meaning of "the *Pokershi…