I couldn't find the answer to this on the TSA website, did I miss it?

Under Secure Flight, the ID you use must match the ticket name, but how specifically are middle names handled? Consider the following 4 cases:

1. Ticket= John Doe, ID=John Robert Doe
2. Ticket= John R. Doe, ID= John Robert Doe
3. Ticket= John Robert Doe, ID= John Doe
4. Ticket= John R. Doe, ID= John Doe

My thinking is that #1 and #2 is okay, since the ID is more specific than the ticket, but #3 and #4 are not.

In all cases, assume the correct DOB is in the reservation.

The reason for the question is that I'm trying to book some US domestic tickets today for family members coming from overseas, and I won't be able to verify exactly how their middle names appear (or don't appear) in their passports for a couple of days, at which point the cheap seats might be gone.

So if I get tickets issued as per option 1 above, will that pose a problem or not?

And yes, I know full well the whole concept of ID check for security is pointless theater, don't get me started!