BAdI definition BADI_SD_SALES_ITEM is only provided for SAP internal use

Hi Experts,

While implementing the BAdI defination i got the error message like "BAdI definition BADI_SD_SALES_ITEM is only provided for SAP internal use ". can u tell me how to implement this BADI, plz provide me steps and don't give links.

for good answer points will be given.

Thanks & Regards.

Priya Papana.