FSML (Financial Services Markup Language) is a data description language based on the Standard Generalized Markup Language (SGML) that was developed to create financial documents for delivery over the Internet, including eCheck and their associated documentation. Like the Hypertext Markup Language (HTML), FSML is a set of markup symbols or codes that allows its users to define the individual items that compose a document, assemble items into larger document parts that take on a contextual meaning, and enable the screening of a document for digital signatures, endorsement, additions, or deletions.
FSML was created to ensure that eChecks could be transmitted by e-mail without being corrupted or invalidated by the particular e-mailing system in use. In order to make sure that all data contents are defined as specifically as possible and therefore may be processed by a software application in their entirety, FSML requires precise adherence to definitions of syntax, semantics, and all values associated with data elements.
FSML is designed to support a full range of payment mechanisms, including electronic checks, Automatic Clearing House (ACH) payment authorizations, ATM network transaction authorizations, and variations of a check, such as a postal money order or gift certificate. In the near future, FSML is expected to conform to the Extensible Markup Language (XML).