"X-" fields may be created for

experimental or private purposes, with the recognition that the

information they contain may be lost at some gateways.

Future values, except for

experimental values beginning with "X-", must be

registered with IANA, as described in RFC 2048.

A media type value beginning with the characters "X-" is a private

value, to be used by consenting systems by mutual agreement. Any

format without a rigorous and public definition must be named with an

"X-" prefix, and publicly specified values shall never begin with

"X-". (Older versions of the widely used Andrew system use the "X-

BE2" name, so new systems should probably choose a different name.)

In general, the use of "X-" top-level types is strongly discouraged.

Implementors should invent subtypes of the existing types whenever

possible. In many cases, a subtype of "application" will be more

appropriate than a new top-level type.

/ x-name) ; A non-standard, experimental

; calendar system name.

; Names are case insensitive,

; but uppercase values are preferred.

To make iCalendar objects extensible, new component, property, or

property parameters can be used. Two types of extensions are defined

by [RFC5545]: IANA-registered tokens ("iana-token") and experimental

use tokens ("x-name"). A client SHOULD save "iana-token's" and MAY

use them in replies. A client MAY save "x-name's" and MAY use them

in replies. When delegating or forwarding messages to other CUs, a

client SHOULD include "iana-token's" and "x-names's".

The extensions properties are always prefixed by "x-" and can have any valid JSON format value.

x-{other} The API's authentication relies in another authentication method.

^x- Any Allows extensions to the Swagger Schema. The field name MUST begin with x-, for example, x-internal-id. The value can be null, a primitive, an array or an object.

Standard keywords are

defined in The Dublin Core Metadata Element Set [RFC5013] and DCMI Metadata Terms

[DCMITERMS]. Vendor or customer-defined keywords MUST use the prefix string "x-" to

avoid future keyword name conflicts, for example "x-vendor-foo" or "x-customer-bar".