The Writer's Desk Book / Being a Reference Volume upon Questions of Punctuation, Capitalization, Spelling, Division of Words, Indention, Spacing, Italics, Abbreviations, Accents, Numerals, Faulty Diction, Letter Writing, Postal Regulations, Etc.

by William Dana Orcutt

WRAPPING OF MAIL MATTER

All mail matter should be so wrapped as safely to bear transmission without breaking, or injuring mail bags or the contents of mail bags or the persons of those handling them. Second, third, and fourth-class matter must be so wrapped or enveloped that the contents may be examined easily by postal officials. When not so wrapped, or when bearing or containing writing not authorized by law, the matter will be treated as of the first class.