10.3(a) states:

Any MAD_Join.indication, or any MAD_Join.request issued by the MRP
application, received by MAP from a given Port in the set is propagated 
as a
MAD_Join.request to the instance(s) of MAD associated with each other 
Port in

the set. If the value of tcDetected (13.23) for the Port and MAP Context is
nonzero, then the value of the new parameter in the propagated 
MAD_Join.request

is set TRUE, regardless of the value of this parameter in the indication or
request that is being propagated.


The existing text is unclear as to which "Port" is referenced in the 
statement
above "If the value of tcDetected for the Port..." as it could refer to 
either:

"received by MAP from a given Port" (the ingress Port)
or
"each other Port" (egress Ports)
in the preceding text of 10.3(a).


It has been suggested that “the Port” refers to “other Port” (the egress 
port).


However, if it refers to the ingress port, it would seem to be more 
consonant

with the purpose of 'new'.
Specifically:
If a bridge has some attribute registered on a port, and that bridge is
connected to another bridge, when the ports begin forwarding, 10.3.d is
invoked, causing the newly-forwarding port to transmit a declaration
If “the Port” is the egress port, the declaration will not be signaled as a
new declaration (10.3.d says nothing about propagating as new). However, if
“the Port” is the ingress port, the neighboring bridge would propagate a
received JoinMt or JoinIn as New, thus informing the bridged LAN of the
topology change