An IS document type defines the structure and type of data in a document (also known as an IData object). In FIX Module, IS document types correspond to each of the FIX message types that FIX Module supports.

You can use an IS document type to build a document or a document list field and define it as the blueprint for pipeline and IData object validation. FIX Module also uses the data stored in IS document types to transform outgoing FIX IS documents into standard raw FIX messages (using the wm.fix.format:convertIDataToFix service). FIX Module provides you with the flexibility to define custom fields, as needed, in the IS document type. For more information about defining custom fields, see Creating Custom Fields. FIX Module also provides an IS document type for processing unidentified fields.