There was a good post on this subject a couple weeks ago, but unfortunately, I haven't been able to dig it out yet.
I think that the indebtedness was originally treated as a ledger entry only, no bonds, notes or documentation of any kind, but now there is some form of paper, but I believe that it is of an unusual kind.
Similarly, since this is basically a current account transaction, I do not believe that this indebtedness is included in the National Debt. I would be extremely surprised if it is, since it is purely an internal government accounting transaction.
When the Democrats state that the SS system is solvent until 2043 they MUST be applying what is owed the system by the federal government. Don't you think so?
Within this framework the funds were transferred and do exist as a form of obligation between the funds and bear interest at the lowest possible rate.
See #40.