I wasn't familiar with etags, so for anyone else curious I'll save you the google search: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ETag https:

I wasn't familiar with etags, so for anyone else curious I'll save you the google search: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ETag https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ET... >If the resource at a given URL changes, a new Etag value must be generated. Etags are therefore similar to fingerprints and might also be used for tracking purposes by some servers. A comparison of them allows the determination of whether two representations of a resource are the same. They might also be set to persist indefinitely by a tracking server.