ETag
Also written: If-None-Match
A fingerprint the server sends with a file. The browser sends it back in If-None-Match to ask whether the file changed, and an unchanged file gets a bodiless 304.
Also written: If-None-Match
A fingerprint the server sends with a file. The browser sends it back in If-None-Match to ask whether the file changed, and an unchanged file gets a bodiless 304.