TheCodeBreakers
Then we take
the words we wish to write, and put them
on paper, writing them not too close together. Then over each of the
letters we place a letter of our countersign in this form. Suppose, for
example, our countersign is the little versetto VIRTUTI OMNIA PARENT.
And suppose we wish to write these words: Larmata Turchesca partira a
cinque di Luglio. We shall put them on paper in this manner:
VIRTUTI OMNIA PARENT VIRTUTI OMNIA PARENT VI
larmata turch escapa rtiraac inque dilugl io"
The keyletter that is paired with a given plaintext letter indicates the
alphabet of the tableau that is to be used to encipher that plaintext
letter. Thus, / is to be enciphered by the V alphabet, a by the I alphabet,
and so on. The system permits great flexibility: no longer did all
messages have to be enciphered with one of a relatively few standard
sequences of alphabets, but different ambassadors could be given
annaabi.ee 
