Nuts and Bolts: in litt.

People still use Latin abbreviations in English text quite a lot.

No, I don't really know why, either.

Some abbreviations are so commonly used that they've become as English as any other word. Et cetera, as etc, is used all over the place, and everybody knows what it means. The same is true of eg and ie (though these are pronounced one letter at a time, and not by their expanded forms as etc is. In the cases of eg and ie the expanded forms are exempli gratia and id est, respectively).

Anyway, apart from these and a few other examples (CV, N.B.) one cannot help but wonder if the only point of Latin abbreviations is to puff up the intellectual credentials of the writer.

Such a one is in litt, which I came across recently in a book on natural history designed for the general reader. It came, rather often, in a series of footnotes attached to quotations from authorities. 

Okay. Do you know what in litt means? 

Can you guess what in litt means?

(In my own case, the answers to these questions were no and no.)

Does in litt express a concept for which there is no easy English alternative?

No.

Does the use of the abbreviation in litt tend to induce extra respect for the author?

Not in my case, no.

Did its presence again and again finally result in reference to a dictionary?

Yes. 

So something was learned, then?

Yes. I suppose so...

...but, look, I'm still really irritated, okay?

Expression Probably Not To Use Today: in litt. This stands for in litteris and means in correspondence.