SUBSTITUTIONS 

@osuccess, @ofail and @odrop messages may contain %-substitutions, 
which evaluate to gender-specific pronouns if the player's gender is 
set. They are: %s (subjective) = Name, he, she, it. %o (objective) = 
Name, him, her, it. %p (possessive) = Name's, his, her, its. %n 
(player's name) = Name. %a (absolute possessive) = Name's, his, hers, 
its.  %r (reflexive) = Name, himself, herself, itself.  If you need a 
'%', use %%. If you want the  pronoun to be capitalized, use a capital 
letter for the substitution, like %S, %P, and so on.  Example: '@ofail 
teapot=burns %p hand on the hot teapot.  %S screams in agony.  Hot 
water spills on %o, and %s he whimpers to %r that he should be more 
careful in the future.' 

See GENDER.