HP PCL/PJL reference - Printer Job Language Technical Reference Manual

2-6 PJL Command Syntax and Format EN
The placement of white space in PJL commands depends on
its location within the command. Some white space is required
and some is optional:
White space is required between the @PJL prefix and the PJL
command name, and between the PJL command name and
command modifiers. For example:
@PJL OPMSG DISPLAY or
@PJL ENTER LANGUAGE = personality
If white space is shown in any other place in the command, it is
optional (see the examples below).
If white space is not shown between two portions of a
command, white space is not allowed. An example is between
the optional carriage return and required line feed character
that terminate most commands.
For clarity, this manual consistently shows white space as one blank
space. The PJL language requirements are shown in both examples
below: