  The presentation of the algebra of classical observables of the closed
bosonic Nambu-Goto-String in 3+1 dimensions is given for the massless case
$P^2=0,P\neq0$ in the relevant standard frame up to and including the second
stratum. The elements and the relations of this algebra established so far are
presented in the form of irreducible multiplets of the stabilizer group $E_2$
of the light-like vector $P$ in its standard form.

High Energy Physics - Theory