(computing) An alphabetical identifier assigned to a drive or volume on MS-DOS or Windows.

(US, law) A written agreement between a prosecutor and a defendant or prospective witness, allowing the latter to give the prosecutor information about an alleged crime, while limiting the prosecutor's ability to use that information against them.

(philately) A sheet of paper that may be folded (and often sealed) and mailed without the use of an envelope.

plural of letter sheet

An italic capital letter with top and bottom flourishes, intended to fill an unsightly gap.

(law) A collective bargaining agreement that is not part of the underlying or primary collective bargaining agreement used by the parties to the contract.

A pair of scales for weighing a letter to determine the cost of postage.

plural of letter balance

(law) power of attorney

(poetry) The repeated letter or letter sequence in alliteration.