You call
Description:Information provided in the Via HTTP response header for proxied
requests
Syntax:ProxyVia On|Off|Full|Block
Default:ProxyVia Off
Context:server config, virtual host
Status:Extension
Module:mod_proxy
This directive controls the use of the Via: HTTP header by the proxy. Its
intended use is to control the flow of of proxy requests along a chain of
proxy servers. See RFC 2616 (HTTP/1.1), section 14.45 for an explanation
of
Via: header lines.
* If set to Off, which is the default, no special processing is
performed.
If a request or reply contains a Via: header, it is passed through
unchanged.
* If set to On, each request and reply will get a Via: header line
added for
the current host.
* If set to Full, each generated Via: header line will additionally
have
the Apache server version shown as a Via: comment field.
* If set to Block, every proxy request will have all its Via: header
lines
removed. No new Via: header will be generated
As example.
You need to go back to school and Apache documentation needs serious updates.
For non serious people such a documentation is ok.