no written referance, just life experience:
we get these v/s clearances a lot over germany like:
"xxx, descent level 300, 2000 feet per minute or greater"
and when recieving lower level, while still in the descent, they often say something like:
"xxx, descent level 240, given rate"
sometimes they also have us report our given rate to the next sector.
On that subject, i have a question to you controllers:
if descending at 2000fpm, i am going to reduce it to maximum 1500fpm when i get to a 1000' from my cleared level. is it something you expect?