One or more lines of information at the start of a file are usually sent to a printer before it starts to print a page. These prepare the printer so that it is set up ready to print the page. For HP-compatible printers, this code is in "PJL" and known as the 'Preamble'. For Xerox printers, the code uses "XRX" commands. EscapeE 'eE' iconEscapeE can propagate PJL and XRX code as a Preamble when exporting to PCL, PostScript, PDF and PDF/A formats.
Most users need not know about these technicalities, but EscapeE enables experts to create specialist data-fields from these lines of code. See PJL prefix and Special fields in composed strings.

Click to expand/collapse hidden textPreamble

The Preamble is made up of lines of code which may be commands for the printer to execute and/or Comments. Comments are there to aid the Operator and are ignored by the printer. You may view a document's comments on the PJL page of the Console notebook.
The total number of characters in each line of the preamble must not exceed 255 but the Composite field syntax can be used to build up longer strings or to copy information from the input.
If a PCL file's preamble strings do not begin with an 'Escape' character it is assumed to be PJL. EscapeE outputs an "enter PJL" sequence and begins each preamble line with:

@PJL

ending the preamble with:

@PJL ENTER LANGUAGE=PCL.

See also the two corresponding command-line options:
/PCLPREAMBLE and /PSPREAMBLE.
Click to expand/collapse hidden textPJL Comments

Any PJL Comments found in the input document's Preamble can be passed to a document on export to some formats:

•PCL: Choose PCL document output format from the General page of the Configuration dialog (f8) then click the Options... button.
oTick Export PJL comments.
•PDF, PDF/A: Choose PDF document or PDF/A document as the output format (from the General page of the Configuration dialog) then click the Options... button.
oTick Export PJL comments.
•PostScript: Choose a Postscript output format from the General page of the Configuration dialog (f8) then click the Options... button.
oClick More... button and select an 'Include PJL comments' format option: XML or Plain text. See More options for PS export.

Up to 26 of these Comments (and also the JOB and JOBATTR commands) from the original file may be associated with each page. They are output as Plain text or as XML-style strings, labeled alphabetically. A typical line in a PDF might be:

% <RT A='COMMENT &34;HEADER PCL&34;' B='COMMENT &34;Driver version 02.03&34;'/>

(Note that the UNICODE hex code 34 is used to output the double quote character.)
Or in Plain text:

% COMMENT "HEADER PCL" % COMMENT "Driver version : 02.03"

Comments may be specified on the command line using /COMMENTS option.

Blue diamond bullet Tip:  a PJL command of the form

@PJL COMMENT REDTITAN DIR xxxx

will cause the special field {_RT} to have the value xxxx.

Blue diamond bullet Notes

When the 'Ignore' PJL commands option (on the General page of the Configuration dialog) is ticked, any PJL commands found in the input file are stored but cannot be exported. They may, however, be used to provide values for fields using the prefix mechanism. In general usage, this specialist feature can be safely ignored.
If the Ignore PJL commands check-box is cleared, PJL commands found in the input file are stored and will be included in the exported file. PJL commands constructed using the prefix mechanism may also be exported.

There is an option to remove unwanted PJL from the output file – for example, when outputting to a printer which is not strictly PCL compatible. Display the Configuration dialog's 'PCL document' options page (see PCL export options) and tick Do not use PJL commands.

Links
PJL Comments

Special fields in composed strings