There isn't one. Several Watchtower references might apply:
I think this is the one that some elders are operating under:
*** w56 6/15 p. 383 Questions From Readers ***
. A disfellowshiped person is no member of Jehovah’s congregation and may not be served the emblems by those serving at the celebration of the Lord’s evening meal
However, more recent references clearly indicate that those who attend and are disfellowshipped should be served:
*** w58 8/1 p. 478 Questions From Readers ***
It is not for you or anyone serving the Memorial emblems to act as the judge, but to allow the emblems to go to anyone in the audience as these are passed along in the normal manner of letting each one have the opportunity to partake.
*** w76 2/1 p. 76 “Keep Doing This in Remembrance of Me” ***
. We do not invite disfellowshiped persons to attend. But if such a one is present, there is no reason to be disturbed if he is seated in a row with others and proceeds to partake of the emblems. Such a one is not counted, in any case, as a partaker.
This implies he would be served, otherwise he would not be able to partake.
Just curious, what part of the world are you in? If in the USA what part of the country are you in generally?
CC