While proposed characters may have been approved by the Unicode
Technical Committee (UTC), they are not yet part of the Unicode
UTC and ISO/IEC
JTC1/SC2 (the subcommittee responsible for ISO/IEC 10646)
synchronize the character repertoire and code points of their
respective standards: characters are not added to one standard
without being approved for the other.
ISO process is by nature lengthier than the Unicode process. A
proposal goes through the following stages before acceptance:
- Initial Proposal:
A proposal document has been submitted to WG2 and is included
in the formal document record. The proposal may not yet have
been taken up on the agenda of a WG2 meeting, or may have
had been included pro forma on an agenda, where it is simply
raised FYI to the attention of national bodies, inviting them
to review and provide feedback on the proposal.
- Provisional acceptance by WG2:
A proposal has been technically reviewed by WG2, with feedback
from one or more national bodies and liaison organizations such as the Unicode
Consortium, and a consensus has been
reached within WG2 that a character, group of characters, or
a repertoire for a script should be encoded. However, a
final resolution specifying code positions and character names
may not yet have been taken or approval may be postponed
pending further feedback from national bodies regarding one
or more technical issues in the proposal.
- Final acceptance by WG2 - in Bucket:
A formal resolution has been taken by WG2, specifying code
positions and character names for addition to the standard,
but without necessarily determining which amendment they
should be included in for formal balloting. This status is
referred to as "being in the bucket," a holding category
waiting for an appropriate amendment. This stage is
transitional and typically is only used when WG2 has a meeting
that does not authorize a formal amendment to 10646.
- Hold for Ballot in WG2:
A formal resolution has been taken by WG2, specifying exactly
which of any characters approved and "in the bucket" are to
be balloted in an amendment to 10646. Note that in current
practice, most character approvals move directly from Stage 1
to Stage 4, for efficiency, unless there is some technical
issue with them or unless WG2 decides that it needs to wait
before starting to progress a new amendment.
- SC2 Ballot: This stage comprises one or more formal
ballots by the member bodies of the parent committee, SC2. During
each ballot, member bodies and liaison organizations (such as the
Unicode Consortium) review the collection of characters and scripts
in the ballot document and provide technical and editorial feedback.
After each ballot is completed, WG2 meets and resolves the comments.
This stage can take a year to two years, depending on the schedule
of ballots and of WG2 and SC2 meetings. Technical changes to the approved characters
may still occur as part of this process, including the addition of characters that
were not originally on the ballot.
Stage 5 begins as soon as SC2 has approved the WG2 resolution to
ballot some collection of characters and the Secretariat has
issued the formal amendment ballot. In the first ballot phase
the draft is known as a PDAM (Proposed Draft Amendment).
After resolution of PDAM ballot comments by WG2, an FPDAM (Final Proposed Draft Amendment) is issued for ballot, followed finally by the resolution of FPDAM ballot comments by WG2.
- JTC1 Ballot: The parent committee, SC2, has approved a resolution to submit
the DAM (Draft Amendment) for approval by the national bodies
at the JTC1 level. During this stage, which is generally
pro forma, there can be no technical changes to the ballot
text. This is a two month ballot, and the issuance of the
ballot is the point at which Unicode implementers can feel
secure in implementing the corresponding, synchronized
repertoire in the Unicode Standard. When the DAM ballot is
approved, JTC1 considers the amendment fully approved,
- ITTF Publication:
An approved amendment to 10646 is submitted to ITTF for formal
publication. An amendment to a standard (or the standard
itself) is not actually considered an International Standard
until ITTF has completed publication. Depending on the
complexity of the standard and any editing issues which
may turn up, this may take several months to more than a
year from the completion of the DAM ballot itself.
The Unicode Consortium has designed its process to be responsive to
market requirements since its members consist of companies, research
institutions, and various other entities. The ISO process
serves a different constituency because it is made up of the
national standards organizations of countries, whether large or
small, that wish to be involved. As a result, final ISO
approval of new characters can occur a long time after they have
been approved by the UTC. Conversely, in some instances a character or group of
characters may reach Stage 4 or even Stage 5 in the ISO
process before they have been formally considered for
approval by the UTC.
During the period when the ISO process is not complete and
when the UTC may still be in the process of synchronizing
character approvals, use of proposed characters is at an
implementer's own risk. The repertoire and allocation of the
characters may change before they are published in a particular
version of the Unicode Standard.