Questioned document examination (QDE) is the forensic science discipline pertaining to document

Document

The term document has multiple meanings in ordinary language and in scholarship. WordNet 3.1. lists four meanings :* document, written document, papers...

s that are (or may be) in dispute in a court of law. The primary purpose of questioned/forensic document examination is to answer questions about a disputed document using a variety of scientific processes and methods.
Many QD examinations involve a comparison of the questioned document, or components of the document, to a set of known standards.