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

2-8 PJL Command Syntax and Format EN
Strings. Enclosed in quotation marks, strings consist of any
combination of characters from Roman-8 character 32 through
255, plus character 9 (horizontal tab), excluding character 34
(quotation marks).
Examples of valid strings include:
"<HT>This is a valid string."
(Tabs are allowed in strings)
"Print job #4655"
Examples of invalid strings include:
"This is not a valid" string."
(Strings cannot contain quotation marks)
"This is also not<CR>valid."
(<CR> is not within the valid range of characters for a string.)
Note Strings displayed on the printer control panel are generally displayed
using the Roman-8 symbol set. On HP LaserJet 4PJ, 4V, and 4MV
printers, when the language is set to Japanese, strings which
correspond to a control panel message are displayed on the control
panel using the JIS X0201-76 character set.
This is also true for some other printers/languages. See the note on
page 8-3.