N1705 Datasheet, PDF (2/2 Pages) List of Unclassifed Manufacturers – 7-bit and 8-bit codes and their extension

Collections are defined in the latest Technical Corrigendum (COR.2) to 10646-1: 1983 (E),
which was recently balloted in SC 2 (Ref. ISO/IEC JTC 1/SC 2/WG 2 N 1664; Draft Technical
Corrigendum No. 2 to ISO/IEC 10646-1:1 1983 (E))
4.11: collection: A set of coded characters which is numbered and named and which consists
of those coded characters whose code positions lie within one or more identified ranges.
Note - If any of the identified ranges include code positions to which no character is
allocated, the repertoire of the collection will change if an additional character is assigned to
any of those positions at a future amendment of this International Standard.
4.17: dense collection: A collection in which every code position within the identified
range(s) has a character allocated to it.
Note - The repertoire of a dense collection can not be extended at a future amendment of this
International Standard unless one or more of the identified ranges of code positions is
extended.
Annex A of 10646 lists a number of sub-repertoires of 10646. The COR.2 has marked some of
these as 'dense collections' based on the definitions cited above.
Note: There is another US / Canada contribution proposing a revisiting the above definitions and
proposing removal of the part 'unless one or more ... ' in the Note under the definition 4.17 above.
Also, note that the words 'extended at a fture amendment' should be changed to 'extended by a
future amendment' in both the above clauses.
Sub-Repertoire of 10646 as Collections
A sub-repertoire of 10646 consists entirely of a set of coded characters defined in the standard. A
'dense collection identifier' can be assigned to any such sub-repertoire by giving it a number, a
suitable name and the list of one or more contiguous ranges of the code positions assigned to
these characters in the standard. The standard already has a listing of the code positions and
names of characters assigned to that code position, and there is no need to replicate this
information in the sub-repertoire definition. At present, a request to ISO/IEC JTC 1/SC 2 (which
will be assigned to ISO/IEC SC 2/WG 2) to issue a collection identifier and enter that into the
Annex A of the standard is all that is needed to identify such a sub-repertoire.
The existing procedure to add a collection identifier is through a 'technical amendment' to the
standard, since Annex A is a 'normative' annex of the standard. Even though this procedure is
more complex and cumbersome than a simple registration procedure, it can be effectively used to
handle the requests for registration of sub-repertoires of 10646. A request for identifying a sub-
repertoire can be prepared and submitted by a member body, a liaison organization or an
individual expert to SC 2, along with some background information and rationale behind the
request.
It is further proposed that the existing 'technical amendment' procedure be retained as it gives the
maximum amount of filtering and control of requests for identifying sub-repertoires by ISO at the
same time being able to respond responsibly to legitimate requests.