"Sign your full name in blue or black ink inside your passport. For children under 16, parents should print the child's full name on the signature line, sign the parent's name next to it, and state the relationship with the child, such as mother, father, or guardian."
Umm, what if you can't sign your name? Will any scribble suffice, or do my markings need to be distinctive and repeatable? What's the purpose of this signature? I have no other active government identification for means of comparison. How is it that my circumstances are not addressed by this pamphlet?
I come across similar situations from time to time. I recently tried to verify my identity to Google and was instructed to hold a valid government I.D. next to my face and take a picture. The example showed the outline of a person holding what is obviously a driver's license. At that time, before receiving my replacement passport in the mail, I didn't have any I.D. If I had, I would not have been able to hold it as instructed. Had I no mouse-controlled camera at the top of my computer monitor, I couldn't have taken the picture anyhow. When I decide to revisit, I'll need to ask for help. Hopefully an extra hand holding my passport won't cause any malfunction.
Tinder's verification process was even more difficult, indeed, impossible. In order to get that check mark in the little blue circle, I was required to hold an open hand next to my face for a picture. I believe they wanted my right hand―doesn't matter. I can't lift my hand into that position and I can't straighten my fingers as instructed. If they gave another option, it wasn't readily apparent; I gave up on it quickly.
Of course, these things aren't a big deal; I'll find a way through them if I have to. But it'd be nice to be part of the norm. It'd be nice to not have to find my own way. And barring that, it'd be nice for people to know I exist.