Meaning of diplomatics

dip•lo•mat•ics

Pronunciation: (dip"lu-mat'iks), [key]
— n. (used with a sing. v.)
  1. the science of deciphering old official documents, as charters, and of determining their authenticity, age, or the like.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.