How to read out the service ID and model number from HP printers via PJL

As the headline says: Does anybody know how to read out the service ID and the model number from HP printers via PJL?

In general, I am familiar with the process of using PJL for such tasks (e.g. reading out the serial number). I just could not find the variable names for the model number and the service ID.

If it matters, I am especially interested in doing this with color laser printers like the CP5225 and the bigger ones.

For those who haven't done this yet:

1) Install your networked printer normally (port 9100).

2) Open bash (Linux) and do the following:

> nc <IP of your printer> 9100 <-- Type this in bash
@PJL INFO PAGECOUNT            <-- Type this when being connected
4589                           <-- This is the printer's response
...                            <-- and so on

I have tried all sorts of INQUIRE and INFO commands which have come to my mind without success, so further guessing seems to be a waste of time.

Does anybody know the respective variable names, or can I somehow make the printer report all variables it supports?