Outside of the InfoCenter Printing topics — Best guess for what you need is the <a href=”http://www-01.ibm.com/support/docview.wss?uid=pub1sc41571306″>Printer Device Programming</a> manual.
It might not be easy picking out the particular detail that you’re after. Skim through the table of contents, then go straight to Appendix D. — Working with Fonts, Font Character Sets, Code Pages, CHRIDs, and Coded Fonts. Read the first couple pages or so before deciding to go through the rest of the appendix or to hit other sections. You can scroll fairly quickly through it to catch tables and lists.