  A mass-independent texture is a set of linear relations of the fermion
mass-matrix elements which imposes no constraint on the fermionic masses nor
the Majorana phases. Magic and 2-3 symmetries are examples. We discuss the
general construction and the properties of these textures, as well as their
relation to the quark and neutrino mixing matrices. Such a texture may be
regarded as a symmetry, whose unitary generators of the symmetry group can be
explicitly constructed. In particular, the symmetries connected with the
tri-bimaximal neutrino mixing matrix are discussed, together with the physical
consequence of breaking one symmetry but preserving another.
