authentic text; original document
Refers to the genuine, original text as opposed to a copy or duplicate. Often used in legal, historical, or archival contexts. Compare with 正文 (せいぶん) meaning 'body text' or 'main text'.
See also: 正文 (せいぶん)
The authentic text of this contract is kept in the safe.
古文書の正文と写本を比較する。
Compare the original document of the ancient manuscript with its copy.
The reading しょうもん is a Sino-Japanese compound (音読み) of 正 (しょう, 'correct') and 文 (もん, 'text'). The specific meaning 'authentic text' is a specialized legal and historical usage.