JS-002 (Annex C) - Procedure for determining Csmall and not to test devices smaller than 4mm X 4mm?

Dear all,

I noticed that JS-002 (Annex C)describe ICDS (Integrated circuits and discrete semiconductors) Csmall and I have no idea why standard mention about this information. Could you please help explain this topic to me ? Also, why the procedure ask us beware of package size and vacuum hole?

JS-002 recommending not to test devices smaller than 4mm X 4mm?

Bruce