This note contains the statements of several results concerning necessary optimality conditions for the optimal control problem of minimizing J(t_1,t_2,x(t_1),x(t_2)) subject to x'(t)in F(t,x(t)) a.e., x(t)in Gsubset bold R^n for all tin[t_1,t_2], (t_1,t_2,x(t_1),x(t_2))in Psubset bold R^{2n+2}. par The first theorem states a Hamiltonian form of the maximum principle which, in addition to known results [F. H. Clarke, {it Optimization and nonsmooth analysis}, Wiley, New York, 1983; [msn] MR0709590 (85m:49002) [/msn]; P. D. Loewen and R. T. Rockafellar, SIAM J. Control Optim. {bf 32} (1994), no.~2, 442--470], contains continuity and jump properties of the Hamiltonian along extremals. The latter properties are shown to imply certain nondegeneracy properties of the multipliers under an additional end-point controllability hypothesis. The last theorem contains a stability property of the multipliers with respect to perturbations F_alpha,G_alpha,J_alpha of the initial problem data.