Each tmnxBsxCustProtExprEntry specifies an expression
substring match criterion for the custom protocol specified
by the second and third indices tmnxBsxAaGrpPartIndex, and
tmnxBsxCustProtEntryId. The tmnxBsxCustProtExprIndex index
uniquely specifies the expression substring.
Rows can only be created and destroyed by specifying the
tmnxBsxCustProtExprRowStatus if the first index,
tmnxBsxCustProtPolicyVersion, is set to 'admin'.