A few questions about string length

I was wondering if Modartt could answer some uncertainties regarding string length in Pianoteq.

From what I understand, "String Length" controls a superfunction that basically goes something like, "Align the overtones of the string with respect to length calculation components u, v, w, x, y, z, and a..." and so on, without changing the diameter/wrap configuration itself. So, as I iterated before, if you want to hear a short string speak periodically, look no further. However, I would like a more in-depth explanation into what it defines; specifically, whether or not the physical length of the string changes, or merely its periodicity. Second, which string's speaking length defines the baseline parameter (length of lowest string?). And, finally, whether string length defines the whole piano or its speaking length.