# User Agent Support Notes for Server-side Scripting Techniques

This page documents user agent support notes for Server-side Scripting Techniques.

## SVR3: Using HTTP referer to ensure that the only way to access non-conforming content is from conforming content

Because some user agents do not support the HTTP referer header, can be configured not to send one, or are behind a proxy or firewall that strips it out, it is possible that some users will be unable to access the non-conforming content when this technique is implemented.