AT28LV010-20JU vs AT28LV010-20JU-319

What is the difference between the AT28LV010-20JU vs AT28LV010-20JU-319 ?
Is there documentation that explains the meaning of the " -319 " suffix ?

The 319 suffix is used to call out software data protection (SDP) disabled. The SL suffix, per the Product Manager, its not needed.