# Custom variables

**URL:** <https://www.ruby-forum.com/t/custom-variables/194791>\
**Category:** NGINX\
**Created:** [September 10, 2010, 6:19pm UTC](https://www.ruby-forum.com/t/custom-variables/194791 "2010-09-10T18:19:41Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![johnnybutler7](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/8491ac/32.png) [@johnnybutler7](https://www.ruby-forum.com/u/johnnybutler7)\
**Post date:** [September 10, 2010, 6:19pm UTC](https://www.ruby-forum.com/t/custom-variables/194791/1 "2010-09-10T18:19:41Z")

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Hey folks.

I can’t find any information about setting custom variables in the  
config.  
It seems to be possible, but is never mentioned in the documentation as  
far  
as I can tell. For example, here:

[browsers.conf · GitHub](http://gist.github.com/228769)

There are two places where variables are used and referenced. A series  
of  
statements like this:

ancient\_browser msie 4.0;  
ancient\_browser msie 5.0;

Apparently compose an array that can be referenced like this:

if ($ancient\_browser){ …

Then a statement like this:

set $unsupported\_browser\_rewrite perform;

Apparently can then be referenced like this:

if ($unsupported\_browser\_rewrite = perform)

Clearly the first case involves some specialized behavior regarding the  
browser used by the request… but the grammar is really obtuse. Can  
someone  
point me to the documentation that explains all this?

Thanks,  
John