Hi,
the ICAP protocol defines in section 4.3:
"User-defined header extensions are allowed. [... They] MUST follow the "X-"
naming convention [...]"
There are already a bunch of user-defined headers in use, unfortunately only
two of them have been published officialy (X-Client-IP and X-Subscriber-ID in
draft-beck-opes-icap-subid-00.txt), many more have been exchanged between
organisations.
With the growing number of ICAP client and server implementations we see more
and more user-defined headers being introduced.
Unfortunately there are already some with the identical meaning but different
names.
To ensure further interoperability even beyond the standard feature set, I
propose that we publish the X-headers that are in use.
Please find below a first list of headers that I am going to describe in the
next days. Maybe we can simply extend the draft-beck-opes-icap-subid-00.txt
document.
There is also a definition for an OTPIONS response's opt-body format that will
be included in the description.
Knowing that there are more X-headers out there, I invite everybody to send
his/her headers with a short discription so that we can add them to the
document.
As soon as I hear about other headers and get the confirmation that their
description can be published, I will add them as an ongoing process.
Best Regards
Martin Stecher
Current list - has to be extended, specifications will be added:
REQMOD/RESPMOD request headers
X-Client-IP
X-Server-IP
X-Subscriber-ID
X-Authenticated-User
X-Authenticated-Groups
REQMOD/RESPMOD response headers
X-Attribute
X-Attribute-Cacheability
X-Attribute-Prefix
X-ICAP-Profile
OPTIONS response headers
X-Include
OPTIONS response opt-body
Opt-Body-Type: Attribute-List