  We consider an interesting class of braidings defined by a combinatorial
property in an earlier paper. We show that it consists exactly of those
braidings that come from certain Yetter-Drinfeld module structures over pointed
Hopf algebras with abelian coradical.
  As a tool we define a reduced version of the FRT construction. For braidings
induced by U_q(g)-modules the reduced FRT construction is calculated
explicitly.
