@aslakr
Thanks. This is closest to the topic among everything I've seen, but I just can't place where it says unambiguously whether case should be folded or not. For example:
> If an application needs to compare two 'acct' URIs (e.g., for purposes of authentication and authorization), it MUST do so using case normalization and percent-encoding normalization as specified in Sections 6.2.2.1 and 6.2.2.2 of [RFC3986].
..only refer to scheme, host and percent-encoding.