How many times has the itu-r revised the ccir 601 international standard?

Its edition 7, referred to as BT.601-7, was approved in March 2011 and was formally published in October 2011.

So it means it has been revised at least  7 times.

if you go to ask a question say ask, there should be something that looks like this. a camera lens.

yaaa

explanation:

dear i am trying to do ur question