or (en échelon)
Messrs. Smith, Robinson & Co.
713 Chestnut Street
Philadelphia, Pa.
II. Informal. — 1. The same latitude is allowed here as in the matter of the date. It is customary, however, to omit the address in informal or friendly correspondence.
III. Formal. — 1. The address is always placed at the end in formal letters, on the left, below the place and date. Its arrangement may be blocked[15] or en échelon,[15] but this should be the same arrangement as that adopted for the place and the address.
2. In making reply to formal invitations, the address of the addressee is omitted.