SEDOL stands for Stock Exchange Daily Official List, a list of security identifiers used in the United Kingdom and Ireland for clearing purposes. The numbers are assigned by the London Stock Exchange, on request by the security issuer. SEDOLs serve as the National Securities Identifying Number for all securities issued in the United Kingdom and are therefore part of the security's International Securities Identification Number (ISIN) as well. The SEDOL Masterfile (SMF) provides reference data on millions of global multi-asset securities each uniquely identified at the market level using a universal SEDOL code.