Thanks for that J. It would be great if TXS were able to give an unambiguous explanation of what is required to set the vary header.
My host EWD referred me to a site detailing problems with using vary: user-agent
https://github.com/h5bp/html5-boilerplate/issues/414 It would seem that caching can be a problem, for example I found this question and answer on the MAXCDN forum:
Quote:
Q: Internet Explorer is not caching my files because of the VARY Header, but other browsers are! What do I do?
A: Add ⌠BrowserMatch ⌠MSIE■ force-no-vary■ to your .htaccess file or its equivalent for NginX/IIS in order to unset the vary header and allow your content to be cached properly.
|
However, since you have been operating with vary: user-agent AND you use MaxCDN I would have thought you'd have witnessed any problems!?
The cloud of confusion around the use of the vary header makes it difficult to know for sure what the risks of using user-agent actually are!