TRANS13 — locality constraints

The spec says the following about locality constraints:

Page 10-14:

An implementation of the Transaction Service may restrict the
ability for some or all of these objects to be transmitted to
or used in other execution environments, to enable it to guarantee
transaction integrity.

[ The objects affected by this clause appear to be TransactionFactory,
Control, Resource, Terminator, and Coordinator. ]

However:

Page 10-14:

An application can propagate a transaction context by passing
the Control as an explicit request parameter. [...] When a Control
is transferred between execution environments [...].

Either I can propagate a transaction context by passing a Control object,
or I cannot. At the very least, the spec must state clearly which
objects are and are not locality constrained, otherwise I can't write
portable code.

resolved, see below