| Syntax: | valid_referers none | blocked | server_names | string ... |
| Default: | |
| Context: | server location |
| Reference: | valid_referers |
This directive assigns a value of 0 or 1 to the variable $invalid_referer based on the contents of the referer header.
You can use this to help reduce deep-linking from outside sites. If Referer header is not accounted for in the list of valid_referers, then $invalid_referer will be set to 1 (see example above).
The parameters can be as follows:
none means the absence of "Referer" header. blocked means masked Referer header by firewall, for example, "Referer: XXXXXXX".