One key sentence in comment 7(d)(1)-3 to Regulation B applies:
"The method used to establish intent must be distinct from the means used by individuals to affirm the accuracy of information."
Apart from that, it should be on the application, rather than with it, to show that it was part of the application when the application was made. Putting the "intent" statement and initials (or signatures) at the top of the application sets it apart from the application signature to address that sentence quoted above from the comment. But there is no absolute rule on placement other than that sentence.
Ultimately, it is the lender's responsibility to obtain the intent to apply jointly documented at the time the application is made, assuming, of course, that the applicants do intend to apply jointly, wherever the joint intent section is. Where lenders mess up is when they go back and try to get the joint intent statement when the note is signed (or later).
John S. Burnett
Fighting for Compliance since 1976
Bankers' Threads User #8