-field of the winprop to a function that receives the client window
-as its sole parameter, and that returns \code{true} if the winprop
-matches, and \code{false} otherwise.
-
-The class, instance and role properties can be obtained with
-\fnref{WClientWin.get_ident}, and the title with \fnref{WRegion.name}.
+field of the winprop to a function that receives the as its parameters
+the triple \var{(prop, cwin, id)}, where \var{prop} is the table for
+the winprop itself, \code{cwin} is the client window object,
+and \var{id} is the \fnref{WClientWin.get_ident} result.
+The function should return \var{true} if the winprop matches,
+and \code{false} otherwise. Note that the \var{match} function
+is only called after matching against class/role/instance.
+
+The title of a client window can be obtained with \fnref{WRegion.name}.