Web-aware application programs can produce an entity body formed from a CICS® document, or from a buffer of data.
CICS documents can be used as the entity body of an HTTP message. They are created using the EXEC CICS DOCUMENT commands. They can be populated by data specified directly by the application program, and by document templates, which are portions of documents defined as CICS resources or created by another CICS program. Documents and document templates can be stored for reuse.
Alternatively, you can specify a buffer of data created by the application program. You might find this option more convenient for short or simple entity bodies, and it is the only option that enables you to use chunked transfer-coding for the message. However, data created in this way cannot be stored for reuse so easily.