A scrap of paper upon which is written:
REALLY REALLY REALLY REALLY bad idea.
The paper WILL be lost.
While I don't agree with the complexity Sellam has come up with
whatever you do needs to have that level of metadata in the file
itself.
The specific nasty example of this are the hundreds of Whirlwind
paper tapes the Computer Museum has. They are indexed with a part
number. They don't appear to have the index for these numbers.