"The Registration Descriptor shall be the first in the PMT loop and included before the AV1 video descriptor." is unclear and should read something like "The Registration Descriptor shall be the first in the respective elementary stream entry in the descriptor loop and included before the AV1 video descriptor."
"The Registration Descriptor shall be the first in the PMT loop and included before the AV1 video descriptor." is unclear and should read something like "The Registration Descriptor shall be the first in the respective elementary stream entry in the descriptor loop and included before the AV1 video descriptor."
Reported by @bilboed