Thanks for answering.
I am using UCS 4.2
We purchased an HP printer, not listed on this version of hplip. HP recommends upgrading the hplip, however, I have not yet tested the suggestion to create a PPD file. I do not want to take the risk of updating the hplip and give some problem, so I'll follow this path and post the results. Anyway, I think it would be interesting for the team to update the hplip in UCS, since in UCC it is more current, and for compatibility issues with new models. I will keep in touch on the evolution of this case.