BSA — truncatable valuetypes

It seems to me that we have an error (or errors) in our spec. If I am
right I would like to bring this issue to the attention of the FTF during
Denver meeting.
Please help me to find if I am mistaken or not.

My understanding is that for being able to extend BSA spec by
introducing new valuetypes as subclasses of the existing (in BSA
spec) valuetypes, we need to use "truncatable" in our spec. Having it the
"extended" servers can still provide sub-classed valuetypes to the "dumb"
clients (those who understand only the original valuetype). But without
this keyword the extended servers can work only with extended clients.
Which is not what we wanted (remember the discussion with Oxford Molec.
about it).
Also the BSA document says in 1.4.1 that we are going to use
"truncatable". However, we did not.

accepted