How to find out if an element is out of production Is there a way to know if Lego has officially stopped making a certain Lego element?

As an example, from the 580 Lego set, I haven't seen this conveyor belt (along with those wheels and the "Legoland" stamped brick, etc) since the 1970's, so I assume it's out of production:



But is there any official word from Lego that certain elements are no longer in production?
I don't know about official word, but according to BrickLink, that Conveyor Belt hasn't been included as part of a set since 1975, so I think it's safe to say that it's not in production any more.

However, if you're looking to buy one, people are selling them.