By playing with Micah's discovery (which is actually documented on page 39, third line from the bottom of Fig. 13), I have come up with the following potentially useful decorations: $$\bfig \morphism/@{>}|-@{|}/<500,500>[A`B;f] \efig$$ $$\bfig \morphism/@{>}|-@{x}/<500,500>[A`B;f] \efig$$ $$\bfig \morphism/@{>}|-@{o}/<500,500>[A`B;f] \efig$$ $$\bfig \morphism/@{>}|-@{*}/<500,500>[A`B;f] \efig$$ $$\bfig \morphism/@{>}|-@{||}/<500,500>[A`B;f] \efig$$ $$\bfig \morphism/@{>}|-@{)}/<500,500>[A`B;f] \efig$$ $$\bfig \morphism/@{>}|-@{(}/<500,500>[A`B;f] \efig$$ The same ideas also work in native xy-pic and, for all I know, in the matrix version as well. Michael