We describe the sample of energetic single-photon events (E gamma > 15
GeV) collected by L3 in the 1991-1993 LEP runs. The event distributio
ns agree with expectations from the Standard Model. The data are used
to constrain the ZZ gamma coupling and to set an upper limit of 4.1x10
(-6) mu(B) (90% C.L.) on the the magnetic moment of the tau neutrino.