IBM 1725 SLS - Manual (Page 278)

Sessions
QMS 1725 SLS Print System User's Guide D-4
Alternatively, if FTP is used to transmit a document to a QMS Crown
printer supporting the %%Session command, the following ftp com-
mand must be entered prior to sending a file to the printer:
cd no_doc_cmds
The default mode of the FTP protocol for the QMS Crown printer adds
network addressing information, in the form of DOCs, to the start of a
job and this data would also terminate the session.
Session Command
Since each subjob may use a different end-of-subjob argument, the
%%Session: ... command sequence must be inserted at the begin-
ning of each subjob to specify the end-of-subjob argument for that
particular subjob.
Function: Signal the start of a subjob within a session.
Syntax: %%Session: mode argument terminator
Notes: The %%Session command provides two
methods to signal the end of a subjob, end by
count and end by delimiter string. Both methods
may be used within one document, but each
subjob may only use one method.
Parameter: mode argument
Purpose: Specify the argument of the %%Session
command.
Default: none (job does not consist of subjobs)