谁懂 RewriteHeader 指令
To remove header, format string pattern should generate an empty string. For example this rule will remove user agent information from the client request:

RewriteHeader User-Agent: .* $1


And this rule will add Old-URL header to the request, providing a Request-URL as a header value:

RewriteCond URL (.*)
RewriteHeader Old-URL: ^$ $1


This last example will direct all WebDAV requests to the /webdav.asp script by changing request method:

RewriteCond METHOD OPTIONS
RewriteRule (.*) /webdav.asp?$1
RewriteHeader METHOD OPTIONS GET

能给我解释一下么
弄不明白

[解决办法]
不懂