Need another ruling

[bob jenkins]

You won't find the exact definition in the rule book itself. Here's an interp from J/R that will help (note that the FED rule is a little different):

FIELDER- A fielder is "on" or "in" DBT if
(a) he is standing and any portion of his foot is touching an object on
DBT or an area that is DBT.
(b) he has fallen and the greater portion of his body is touching an area
that is DBT.
(c) he is leaping and his leap originated from the surface of an object
on DBT or from an area that is DBT.