NOVELTY - Composition (A) comprises a support and a salt embedded in the support, where the salt is sulfonium salts (1a) or (2a), guanidinium salt (3a), or phosphazenium salts (4a) or (5a).    USE - (A) is useful in polymer (I), which is useful in anion-conducting membrane (claimed), for fuel cells, membrane-based water electrolyzers, and other chemical (e.g. anion-exchange resin and wastewater treatment) or electrochemical (e.g. salt splitting) applications.    ADVANTAGE - (I) provides membranes with enhanced stability to aqueous alkali. (I) provides the membrane, which: is more robust than known anion-conducting membranes because they are less susceptible to degradation than known membranes; is more stable to chemical degradation at high pH; is highly conducting; is not significantly affected by degradation or by the formation of carbonates; and uses non-noble metals instead of noble metals (e.g. nickel instead of platinum), hence cost effective.    DETAILED DESCRIPTION - Composition (A) comprises a support and a salt embedded in the support, where the salt is sulfonium salts of formula ((R5-N(R4)-S+(N(R4)(R5))-N(R4)-R5)(Q-)) (1a) or ((R5-N(R4)-S+(=O)(N(R4)(R5))-N(R4)-R5)(Q-)) (2a), guanidinium salt of formula ((R5-N(R4)-C+(N(R4)(R5))-N(R4)-R5)(Q-)) (3a), or phosphazenium salts of formula ((R5-N(R4)-P(=N+(R5)(R6))(N(R4)(R5))-N(R4)-R5)(Q-)) (4a) or (R5-N(R4)-P(=N(R5))(N(R4)(R5))-N(R4)-R5) (5a).    Either R4, R5 = 1-10C (cyclo)alkyl, 1-10C alkenyl, 1-10C aryl, 1-10C aralkyl or 4-20C heterocyclic group; or    R4R5 = -(CH2)2-, -(CH2)3-, -(CH2)4-, -(CH2)5-, -CH=CH- or -CH=CH-CH=CH-;    R6 = H or (cyclo)alkyl; and    Q = anion, preferably hydroxide, carbonate, bicarbonate or halide.    An INDEPENDENT CLAIM is included for a phenyl group containing polymer of formula (I), with the caveat that the polymer comprises at least 1 wt.% of the residue.    n = 3 or greater;    Z = direct bond or chemical group comprising -O-, -S-, -SO2-, -C(CH3)2-, -C(CF3)2-, -C(=O)-, -P(=O)(aryl)- or phenyl; either    R1, R2 = H or R4; or    R1R2 = -(CH2)2-, -(CH2)3-, -(CH2)4-, -(CH2)5-, -CH=CH- or -CH=CH-CH=CH-; and    A1, A2 = H, R5, sulfonium salts (1a) or (2a), guanidinium salt (3a), or phosphazenium salts (4a) or (5a).