  The quantum commutations $RTT=TTR$ and the orthogonal (symplectic) conditions
for the inhomogeneous multiparametric $q$-groups of the $B_n,C_n,D_n$ type are
found in terms of the $R$-matrix of $B_{n+1},C_{n+1},D_{n+1}$. A consistent
Hopf structure on these inhomogeneous $q$-groups is constructed by means of a
projection from $B_{n+1},C_{n+1},D_{n+1}$. Real forms are discussed: in
particular we obtain the $q$-groups $ISO_{q,r}(n+1,n-1)$, including the quantum
Poincar\'e group.
