Brackets are used only when supplying information not found on the piece or when using the abbreviations "s.l." or "s.n." (LCRI 12.0B1). Do not close the bracket when the field is not complete and no unbracketed information follows (except when supplying the term " distributor"). When supplying information that is doubtful, give a question mark. Example:

See also:

10.1. Sources and bracketing