Finding a symbol item's name (or number)

My script needs to find which of the currently selected symbol items has a particular name (or number, within the Symbols palette), and extract its coordinates.

Cycling through each symbol in turn seems quite straightforward, as does getting the coordinates. But despite looking through the Illustrator Scripting Reference (Javascript) I can't see how to retrieve the symbol's name (or number).

This is probably pretty basic stuff, but I'd be grateful for some pointers.

(And thanks again to all who helped me on my last visit here, about three years ago!)