USPS Pub No. 28 States in part:
232 (my favorite example)
Street Name - Information found in the primary name field of the ZIP+4
File is used as the street name. The ZIP+4 File indicates the preferred
primary street name to ensure that the correctly designated primary
street record is matched  during the address standardization processes.
    The Street Name is the official name as designated by the local
addressing authority - NOT the Zip+4 File!!

213.3 
Allows for alternate Location and 215 the Dual Address issue
    Not useful, and could be confusing, for emergency responders
235 
Numeric street names, for example, 7TH ST or SEVENTH ST, should be
output on the mail piece exactly as they appear in the ZIP+4 File.
    The Street Name is the official name as designated by the local
addressing authority.