When metadating content, you often want to link the precursor i.e. the content it was derived from.
When there is one clear precursor, I use the stem/
prefix:
title = "Weird Al" Yankovic - Foil (Official 4K Video)
maker = alyancovic
youtube = urglg3WimHA
stem/title = LORDE - Royals
stem/maker = Lorde
stem/youtube = LFasFq4GJYM
Sometimes the precursor is not that univocal (because there are two, or so).
Then, I also use a slashed prefix, but not the word stem
.
youtube = WT1wTHjDd3M
title = Statues dancin' all night long
maker = Nap
music/title = Dancin (Krono Extended Remix)
music/maker = Krono
video/title = All Creative Work Is Derivative
video/maker = Nina Paley
video/youtube = jcvd5JZkUXY
When we do this, we build a tree of derived content.
title = Dancin (Krono Extended Remix)
maker = Krono
stem/title = Dancin
stem/maker = Aaron Smith
Think of foreign keys in relational databases.