Postal Explorer >
Publication 28 - Postal Addressing Standards >
2 Postal Addressing Standards > 21 General > 212 Format
Format all lines of the address with a uniform left margin. Uppercase letters are preferred on all lines of the address block.
Lowercase letters in various type styles are acceptable provided they meet postal guidelines for OCR readability. See the DMM for OCR readability requirements that must be met for automation rates (other rates may also apply).