When an ETag is marked weak with "W/", it need not change across different content encodings. "Weak" means the entity is semantically equivalent but not bit-equivalent. But Redbot complains that it doesn't change with different content encodings.
Thanks for the report.
It's a good question. I've raised this for discussion in the HTTPbis WG - see http://www.w3.org/mid/7D2A809E-F3E0-4128-AFEA-8EEEBF3AC26E@mnot.net
Based on that, I'll make changes here as necessary.
Isn't this the same as #113?
Don't flag when conneg produces responses with different weak ETags. …