Nginx Proxy/FastCGI Caching X-Accel-Expires 0 or Off ?

[c0nw0nk]

So in order for my web application to tell Nginx not to cache a page what
header response should I be sending ?

X-Accel-Expires: 0
X-Accel-Expires: Off

I read here it should be "OFF"
https://www.nginx.com/resources/wiki/start/topics/examples/x-accel/#x-accel-expires

But it does not mention if numeric value "0" has the same effect Nor does it
mention if the "off" value is case sensitive or not.

I am hoping case sensitivity does not matter.

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,279752,279752#msg-279752