Hello Chris,
The SDM 12.5 Green Book that Naveen referenced is still online here:
https://search.ca.com/assets/SiteAssets/TEC580893_External/CA_SDM_r125_Green_Book_ENU.pdf
(I did a search for "Green Book" and "SDM Multilingual Considerations".)
Bear in mind that CA SDM has never gone the full multi-lingual route - but it is important to define what you want to achieve by this.
We offer fully localised versions, where the whole user interface is in a different language, such as Chinese. These are available out of the box and work just fine.
And of course the one installation can store any number of languages for the data - provided the database and o/s can handle it. So there is nothing to stop you from putting French data into a standard (English) SDM installation via the user interface. You can even knock up a few of the key forms into French if you wish, and create a French Form Group.
The Green Book is still pretty much relevant . . . but not encouraged, due to the extra complexity and the fact that time and versions have marched on. An alternative is to stand up different boxes per region, and then have a data import/export between them if needed (or give a View/limited Edit login to those who need it). (So no, there is no ITSM 17 Green Book that tells you how to do Multi-Lingual.)
Finally, for any current information, go to DocOps for ITSM 17 and type in "language." Not a lot will come up, but you'll come across things like this:
Configure Unified Self-Service to Support a New Language - CA Service Management - 17.1 - CA Technologies Documentation
Hope that helps. If you need more, you're probably best opening up a new thread to discuss this to get more eyes on it.
Thanks, Kyle_R.