Name: event_content_inclusion_mode
Type: ENUM
Allowed-Values: standard message header body headerbody
Default-Value: standard
Last-Modified: 2.5.0

The mode in which message content may be included with MessageAppend and
MessageNew. "standard" mode is the default behavior in which message is
included up to a size with the notification. In "message" mode, the message
is included and may be truncated to a size. In "header" mode, it includes
headers truncated to a size. In "body" mode, it includes body truncated to
a size. In "headerbody" mode, it includes full headers and body truncated
to a size.
