  In this short Survey we revisit the subject of local, identity-tangent
diffeomorphisms of $\doC$ and their analytic invariants, under two viewpoints:
that of explicit expansions, which necessarily involve multitangents and
multizetas; and that of effective computation. Along the way, we stress the
difference between the \textup{collectors} (pre-invariant but of one piece) and
the \textup{connectors} (invariant but mutually unrelated). We also attempt to
streamline the nomenclature and notations.

Dynamical Systems