These signals are used to be able to blueprint the compact-combinator. As factorio right now has a complicated tag system which I did not bother to use yet. As a user: you should not be able to change them and you should not bother to understand ;)
As a dev: v ( version always 1 right now) , x,y (chunk coordinates), s (size always 19 right now), i (identifer used for blueprinting, the blueprints of the content is stored in the magical chest on the combinator surface which you might see when you build a compact-combinator at 0/0 and enter it).
