  We discuss different aspects of the 2+2-signature from the point of view of
the quatl theory. In particular, we compare two alternative approaches to such
a spacetime signature, namely the 1+1-matrix-brane and the 2+2-target spacetime
of a string. This analysis also reveals hidden discrete symmetries of the
2+2-brane action associated with the 2+2-dimensional sector of a
2+10-dimensional target background.
