A Short Glossary of Professional Correspondence Terms

Business correspondence has its own small vocabulary of conventions and abbreviations, most of which date from the era when letters were typed on physical paper and circulated by mail. The terms are still useful, even in an email-first workflow, because they signal a kind of professional fluency the recipient picks up on. A short glossary covers most of what you'll encounter.

"Attn:" or "Attention:" precedes the name of the specific person who should read a letter sent to a general address. "c/o" ("care of") indicates that the letter is being routed to one party in care of another. "Encl." or "Enclosure" is added below the signature when one or more documents accompany the letter. "cc:" (originally "carbon copy," now retained as a convention) lists the people who are receiving a copy of the letter, named openly. "bcc:" indicates a blind copy, which the primary recipient cannot see; it is widely used in email but generally avoided in formal letters. For a more granular breakdown of the conventions discussed here, see the companion professional drafting reference we maintain alongside this guide.

"Re:" or "Subject:" introduces a one-line summary of what the letter concerns, placed between the recipient's address and the salutation. It is especially useful when the recipient is an organization rather than a person, because it routes the letter to the right desk. "Per" ("per our conversation," "per your request") is a serviceable shorthand but is overused; replace it with "as discussed" or "following up on" when you can. Practitioners who write in regulated industries may also find our compliance-aware editorial checklist a useful next step.

"P.S." (postscript) was originally an afterthought added to a finished letter and is now mostly a marketing convention; reserve it for that context. "Dictated but not read" is a holdover from the era of executive dictation and reads as either pretentious or quaint in modern correspondence; skip it. "Without prejudice" is a legal phrase that signals the contents of the letter cannot be used against the writer in later proceedings; use it only when you understand its legal effect in your jurisdiction.