Q on Variable Omission in Abstract Process

[Yuzo Fujishima <fujishima@bc.jp.nec.com>]

Hi,

Can anyone help me understand the last two sentences
in 15.1 quoted below?

  15. Extensions for Business Protocols
  [...]
  15.1. Variables
  [...]
  If a correlation set is initialized by rule 1 or 2 above,
  then outgoing messages in the same correlated exchange must
  also refrain from referencing a message variable. This
  restriction applies because it is not possible to initialize
  the properties of the outgoing messages from the correlation
  set alone.

Are they saying the following?
* Outgoing messages have more information (especially message
  properties) than correlation sets.
* A correlated exchange must handle the same amount of
  information throughout its lifetime. That is, if a correlated
  exchange begins only with information relevant to correlation
  sets, it must stay within it.
* Therefore, the above restriction.

Yuzo Fujishima
NEC Corporation