MRS (Ms are being used by widows or spinsters(?)
MARRIED NAME (Husband's Family name)
LEAVE IT BLANK (I left it blank when I filed my application)
Some notes:
Example: If Single, the complete name is: Miss Ana S. Cruz
1st Names: Ana
Mother's Maiden Name: Santos
Father's Name: Cruz
Now: with Married name (Husband's Surname: Smith) Fill up form as: MRS ANA SMITH
1st names: Ana
Middle Name: Leave this blank (forget your maiden name: Cruz)
Surname: SMITH
Hope this will make sense... in the UK Middle name is their 2nd name (not the mother's maiden name, as they normally do not use their mother's maiden name)...