如果相同的 URL 可以提供不同的内容类型，应该接受 Vary include 吗？
If the same URL can serve different content types shoud Vary include accept?
如果相同的 URL 可以为同一资源提供不同的内容类型，Vary 必须包含 Accept 吗？还是浏览器缓存和代理将其理解为隐含的？
示例：
GET /some/thing HTTP/1.1
Accept: application/json
这个回复
HTTP/1.1 200 OK
Transfer-Encoding: gzip
Content-Type: application/json
Cache-Control: max-age=3600, must-revalidate
Vary: Transfer-Encoding
{...}
或者这个
HTTP/1.1 200 OK
Transfer-Encoding: gzip
Content-Type: application/json
Cache-Control: max-age=3600, must-revalidate
Vary: Transfer-Encoding, Accept
{...}
实际上 RFC 并不表示对内容类型进行任何类型的“隐式”或特殊处理（接受）header...
A Vary field value consisting of a comma-separated list of names
indicates that the named request header fields, known as the
selecting header fields, might have a role in selecting the
representation.
如果相同的 URL 可以为同一资源提供不同的内容类型，Vary 必须包含 Accept 吗？还是浏览器缓存和代理将其理解为隐含的？
示例：
GET /some/thing HTTP/1.1
Accept: application/json
这个回复
HTTP/1.1 200 OK
Transfer-Encoding: gzip
Content-Type: application/json
Cache-Control: max-age=3600, must-revalidate
Vary: Transfer-Encoding
{...}
或者这个
HTTP/1.1 200 OK
Transfer-Encoding: gzip
Content-Type: application/json
Cache-Control: max-age=3600, must-revalidate
Vary: Transfer-Encoding, Accept
{...}
实际上 RFC 并不表示对内容类型进行任何类型的“隐式”或特殊处理（接受）header...
A Vary field value consisting of a comma-separated list of names indicates that the named request header fields, known as the selecting header fields, might have a role in selecting the representation.