FAA prohibits curtains between cabins?

[BayAreaLondoner]

I was recently flying a US carrier from Europe and was told that the FAA no longer allows the curtain to be drawn between coach and business (and presumably business and first), and that apparently all the curtains would be physically removed in the near future.
I had a quick search both here on Pprune and on Google and couldn't find anything relevant. I'll slog through the FAA site next, but in the meantime, can anyone confirm this, and if possible let me know the regulation that applies?

Many thanks.

[ernest t bass]

I don't believe this is an FAA mandated directive, but many companies are adopting this policy so that the cabin crew can maintain a better awareness of the entire cabin and of the entire crew at all times.

[tinyrice]

As recently as last Tuesday, one major US airline out of LGW continues to close the curtains between the zones, and as yet hasn't issues instructions to the contrary.

[BayAreaLondoner]

Thanks for the replies.
Since my initial post, I have had a look at the on-line FARs and haven't found anything that relates to curtains separating zones. Then again, I haven't found anything that relates to having the curtains open during take-off and landing, and I would imagine that this must be covered by the FARs somewhere...?

Tinyrice's comments are matched by my experience as of yesterday. On the flight from the US, the curtains were closed. On the flight back to the US, some curtains were closed, some were open.