my dad does not have a surname

[krishnaeyyunni]

My dad does not have a surname, just given name and its the same in his passport. the surname field is blank. what should i enter in the surname field in DS156? can i write it as none??

[peace]

Well everyone has a sur name ( family name). In your dad's case it must be an ignorant omission ( no offence please) from his ancestors. Please double check with his municipal birth certificate, his school and college
diplomas if they mention a surname.
I do not know how the embassy will react to it. And it will be in his own advantage to have a last name. After all, one is identified through a last name first and first name second. His father must have had a last name, he could have it added to his passport through an affidavit.