Screenshotted from the (fictitious) "1929 Social Register" in the opening sequence of the film Down to Their Last Yacht (1934).
"Miss Linda Colt-Stratton" I get, but what's the "Jl. Sg." after her name?
My impression from some very cursory Google-Booksing is that typically the Social Register would contain earned titles such as degrees ("M.Sc.", "Ph.D.") or I suppose military ranks, but even if Miss Linda Colt-Stratton were a sergeant, I still don't understand the "Jl." part. Vice versa, I've found "Jl." used as an abbreviation of "July" in one place, but I don't see how that would explain anything, either.
Theories which additionally explain Mrs Geoffrey Colt-Stratton's "Cda." suffix will earn bonus points. :)