Quick question regarding passport photo for G325a and evidence of relationship

[VividDreamer 15]

So, fiancé and I are still working on the I-129f; we decided to submit it when I can look over everything in person during my next visit in a few days (I'm just better at forms and official language than him, lol). Just have a few questions.

I got my passport photos taken May 9th. They put the stamp on the back that has the location, date and then the normal line for "I certify this is a true likeness of ____". Supposed to be for a guarantor signature for a passport application. There's not much room on the back to fit anything else. Should I just write my own name on that line and not worry about how it's labelled as for a guarantor signature, where the requirements just state to label the back with my name and doesn't specify needing another person's signature?

Also, I've read that having letters from friends/family stating knowledge of our genuine relationship is helpful. I've got a few people willing to sign a letter like that. What would I put as a heading for the print out? I don't want to just leave it as an unlabelled sheet because it might get confusing when I make the list of contents for the package and try to out everything in the right order.

Thanks in advance for any help!