Spouce(Wife) doesn't have surname in passport

[pkhera]

Hi,

My wife's passport doesn't have surname and her all documents(educational degrees, pan card, voter card, UID etc.) doesn't have surname printed but while filling DS-160 application form for B1 Visa online, it gives below listed error message:

Spouse's Surnames has not been completed.

Please suggest, how I can proceed on it.

Thanks

[PryncissQueen]

If no Surname use "LNU" for Last Name Unknown