DS -160 form ... can i use LNU for spouse ?

While raising H4 stamping request for my spouse …in all her documents she only used first name …no last name.

so while filling DS-160 form can i write ‘LNU’ in surname field ?

A female married person will either take the last name of spouse, hyphenate own maiden last name with spouse last name or simply retain original maiden name as a personal decision. This is the law in over 150 countries. In the US, a married male can also take female last name. In same gender marriages, the last names may be retained as is or any of the two family names can prevail by choice. ‘Last Name Unknown’ may not be used in legal documents as it is not correct and prevents security analysis of submitted documents.

Best wishes

Dr. Sandeep Shankar