On a letter, “Attn” signifies “attention” and the attention line. The attention line indicates who inside an organisation is to receive a letter or item.
When sending a letter or package to a major corporation, the word “Attn” and the attention line are required. When the communication or parcel reaches the mail department of an organisation, the attention line indicates who the intended receiver is. The attention line is beneficial for persons wishing to correspond with a person in their function as a representative of an organisation, as opposed to as an individual. On a letter or package, the attention line should be put above the organization’s name. Instead of using “attn” when addressing a package, the United States Postal Service recommends senders to simply write the individual recipient’s name above the organization’s name. In a business letter, the attention line appears above the greeting.
Outside of the context of a letter, “Attn” is just a slang term meaning “attention.” The abbreviation is frequently used in non-professional internet interactions and literary works that defy established language on purpose. Attention is described as focusing on a certain object while ignoring all other parts of a given environment, a definition that aptly fits the abbreviation’s application in addressing a piece of mail.