I have this little porcelain box with a picture inside, and underneath the picture it says "I.Reg: CXVIII v 3"
I'm not quite sure it's a "v." There might be subscripts under the "v" and the "3."
Is it a date? The year 118. the Year of the Consulship of Hadrianus and Fuscus. The people in the picture look like they're in ancient Roman attire. Or could it be a passage in something, or a title?
It looks to me like an abbreviated biblical citation, referring to I Samuel 18:3.
inierunt autem Ionathan et David foedus diligebat enim eum quasi animam suam
And David and Jonathan made a covenant, for he loved him as his own soul.
This is a fairly standard form of abbreviation for the Vulgate bible, in use from the Middle Ages onward. Before the modern English use of "chapters" and "verses", the Bible was divided into capitula and versus, here abbreviated (in the singular) as C and v. The I.Reg abbreviates I Regum, or I Kings. This is a Vulgate reference, however; in the KJV, it refers to I Samuel. The line certainly matches the image, which helped locate the passage.