[Tzdist] tz-by-ref ticket #27

[Ken Murchison <[e-mail]>]

All,

Some thoughts on this issue:

As the draft states, testing has already been done and clients appear to 
behave just fine in the face of unilateral omission of VTIMEZONEs in 
server responses.  But, if we feel the need for client opt-in for this 
behavior (I'm not convinced that we do), I see 2 easy options:

1. Trigger client opt-in if/when the client tries to fetch the 
CALDAV:timezone-service-set property.  This is an all or nothing 
option.  If the client loses connectivity with a TZdist server or 
decides that it want to opt-out, the only way to disable tz-by-ref in 
responses is disconnect from the CalDAV server and reconnect.

2. Create a new Prefer request header field 
<http://tools.ietf.org/html/rfc7240> token (e.g. tz-by-ref) which the 
client can send in each GET/PROPFIND/REPORT request in which it expects 
to receive iCalendar data in the response.

My opinion is that unless we hear strong argument(s) from client authors 
that an opt-in mechanism is required, we stick with unilateral omission 
of VTZ data in server responses.

-- 
Kenneth Murchison
Principal Systems Software Engineer
Carnegie Mellon University