PNG Chunk Registration Process, draft 19960926
Status of this Memo
This document is an informal draft of the PNG development group.
Comments on this document can be sent to the PNG specification
firstname.lastname@example.org or at
Distribution of this memo is unlimited.
At present, the latest version of this document is available on the
World Wide Web from
Copyright © 1996 Thomas Boutell
Permission is granted to copy and distribute this document for
any purpose and without charge, provided that this notice is preserved,
and that any substantive changes or deletions from the original are
This document describes the approval process for registering
public PNG chunks. Persons who have contributed to the PNG mailing list
at least 180 days prior to the end of the voting period are eligible
to vote. A two-week voting period follows a two-week discussion
period. Votes are cast by electronic mail to the png-list mailing list.
Approval of a chunk registration requires at least 10 YES votes with at
least twice as many YES votes as NO votes.
Table of Contents
To formally approve or reject a chunk for registration as a public chunk
as described in the PNG 1.0 specification. This method can also be used to
resolve other issues that need to be decided by the PNG group.
Discussions on the PNG discussion list (email@example.com) at
present fail to reach a clear consensus on the desirability of particular
chunk definitions. The formal approval process is intended to aid such
To meet these ends the formal process is based on a discussion and
voting process exercised over a limited period of time.
Identifying consensus when it exists.
Giving a limited time period within which objections can be raised.
Encouraging discussion and preventing ambiguities when one party to the
discussion simply falls silent.
Voting can be initiated after a two-week discussion period. The proposed
chunk specification must be available and must not
change for a period of at least two weeks before a vote can be called for.
The chunk proponent starts this clock running by notifying the list that
the proposed specification is available. Short proposals should also be posted
to the list, to save people the trouble of downloading them. If
discussion exposes flaws, the specification can be revised, thus starting a new
two-week discussion period.
A proposed specification of the chunk must exist in electronic form in a
on the current png-group discussion list FTP server. At present this is the
tree based at
The proposal must be in a final publishable format, such as that of the
PNG 1.0 specification and PNG extensions documents found in
The specification can be a whole single file, a group of files
(which must be named by a single ftp accessible directory name and implies all
files in that directory and all directories beneath it), or an identified
part of a single file.
The specification should describe the proposed chunk in its unregistered form,
to avoid the risk of premature distribution of documents describing
public chunks that are not in their final form.
The editors will make the necessary changes to the final document, by
changing the second letter of the chunk name to uppercase and by removing
any private version identification. If any other changes are needed,
instructions to the editors should be provided in the proposal.
The specification or the call for votes must state the proposed
disposition of the registered chunk:
Note that the names of all formally registered chunks
will either appear in the PNG specification or in the PNG extensions document.
The editors will make the appropriate changes to those documents when a
chunk is registered.
Inclusion in the PNG core specification
Inclusion in the PNG extensions document
Inclusion in an existing separate document
Inclusion in a new separate document
Throughout the two-week voting period the specification must remain
absolutely unchanged. The two-week discussion period must be restarted
upon making any change to the proposed specification, except for
Upon the objection (on grounds that the change is nontrivial) of any
person who would be eligible to vote if the
voting period were to start immediately after the close of the discussion
period, received by the png-list server prior to the call for votes, the
two-week discussion period must be restarted in the event of any such change.
The beginning of the new discussion period will be the time that the message
announcing the change was received by the png-list server.
Trivial formatting, grammatical, or spelling changes that do not change
the meaning of the specification.
A printing date or authorship change.
Any person can initiate the voting period by
submitting the first YES vote on an identified specification. This
message also serves as the call for votes. This message must not
be received by the png-list server before two weeks have elapsed since
the message initiating or reinitiating the discussion period was received
by the png-list server. There is no provision for
issuing a call for votes without also voting YES at the same time.
The message must clearly identify the specification to be voted
upon. Appendix 1 gives the recommended format for a call for votes.
Votes are cast by sending a message to the png-list indicating a YES, NO,
vote. Voters must take care to make their intentions clear (i.e. "YES" or
"NO" or "ABSTAIN" and precisely what chunk specification is being voted on).
It is possible that votes will be tallied automatically. Therefore,
to ensure that a vote is correctly registered, the first five lines of
the message must conform to the following format:
Glenn Randers-Pehrson <firstname.lastname@example.org>
There should be no other topics of discussion in the same message. An
"Oh, by the way, I vote NO on cNEW" buried in the text of a long message
might get overlooked by a person tallying the votes and would most certainly
be missed by an automatic vote tallying robot. It is acceptable and useful
to include additional explanations in the message, but the vote itself must
be placed at the beginning.
The subject of the message must contain the word "VOTE" (in uppercase
and the name of the proposal being voted upon. The string "Re:" must
not not appear in the subject. An example of a correctly formatted
subject line is
Subject: VOTE on cNEW 19991231.
Only one vote should be included in a message. If a group of chunks is being
voted on as a whole, then only one message is necessary, but if
different chunks are being separately voted upon during the same period,
separate messages are required. The decision whether to group or separate
chunks for voting is up to the person casting the initial YES vote.
Persons are expected to identify themselves with their own name and their
preferred e-mail address on the fifth line of the message, regardless of
the account name from which they actually submit the message.
Any votes received prior to the call for votes (i.e. the first YES vote
after the close of the discusson period) will not be counted.
A person can submit a changed vote any time prior to the expiration
of the voting period. Only the latest vote, determined by the time it
was mailed by the voter (from the "Date:" field of the message), that
is received by the png-list server prior to the expiration of the
voting period, will be counted. ABSTAIN votes are not counted. A person
can cast an ABSTAIN vote to withdraw a YES or NO vote without having to
cast a NO or YES to countermand it. The first YES vote, even if
countermanded, continues to serve as the call for votes.
The name and e-mail address on the fifth line of the changed vote must
match those of the original vote, even if the new vote is submitted
from another e-mail account.
The voting period ceases two weeks after the initiation, at the same
time of day as the initiation.
The time of the call for votes is determined by the
"Received:" line generated by the png-list e-mail server, e.g. in the
"Received: from grommit.inria.fr (grommit.inria.fr [22.214.171.124])
by dworkin.wustl.edu (8.6.10/8.6.6.yuck) with ESMTP id KAA10764 for
<email@example.com>; Sun, 22 Sep 1996 10:11:58 -0500"
the date and time are "Sun, 22 Sep 1996 10:11:58 -0500", and the
voting period ends on Sunday, 06 Oct 1996 10:11:58 -0500.
The voting period ceases immediately and the proposal is rejected upon
approval of a competing specification for the same chunk name.
A chunk specification is approved if both of the following conditions are met
at the end of the voting period:
If these conditions are met, then the chunk becomes registered
immediately upon the close of the voting period, and
people can start using it in its registered form. The PNG editors will
include the chunk specification, or a reference to it, in the next release
of the PNG documentation.
Ten YES votes are received.
At least twice the number of YES votes as NO votes are received.
If these conditions are not met the chunk specification is rejected. The
same chunk cannot be brought up again for another discussion period and vote
either until a 180-day waiting period has elapsed, to allow for implementation
and testing, or until a substantial change to the specification is made.
Any person is eligible to vote who has:
The "Received:" field generated by the png-list server is used to determine
the exact times of the the beginning of the discussion period and the
voting period, the close of the voting period, and for all other timing
purposes except that the sender's "Date:" field is used to determine the
order of precedence of multiple votes from the same person.
Adoption of this process for registering PNG chunks will be voted upon
using the same process as used for approving a chunk registration. It
will take effect immediately upon the successful completion of the required
discussion and voting periods. Discussion periods for proposed chunks,
but not voting periods, can run concurrently with the voting period for
adoption of this process.
Submitted their first (or any subsequent) message received by the
png-list server at
least 180 days before the termination of the voting period.
Not voted on the same matter during the present voting period
using a different name or e-mail address on the fifth line of the
If approved, this document will be converted by the editor to a non-draft
form and maintained in the appropriate public documents directory
on the png-group discussion list FTP server.
The process described in this document can also be used in a suitably
amended form for registering chunks in related formats such as MNG,
provided it is separately adopted for use for the other format.
This process depends upon the integrity of the persons involved.
We have no reason to believe that other measures are required. In
the event of a prank or fraudulent vote, we will deal with it
harshly, outside the scope of this process.
This process depends upon the continued availability of the png-list
server and its connection to the Internet. We will deal with system
failures on a case-by-case basis, outside the scope of this process.
This is a recommended format for a call for votes, to be used by the
first person submitting a YES vote. Only the first five lines of the
message, which contain your own YES vote, are mandatory; the rest can
be omitted if it is clear that all participants are already aware of
the voting process. When there has been a long lapse between votes,
or when new people have become eligible to vote, the complete message
should be sent.
Subject: VOTE on CNEW 19991231
My Name <firstname.lastname@example.org>
This is a call for votes on the PNG proposal
To vote on this proposal, send a message to
The subject line of your message must contain the words
VOTE on cNEW 19991231
and must NOT contain the string "Re:" (i.e. do not try to
cast your vote by "replying" to this message. You must
manually construct the proper subject line).
The body of your message must contain the following five
lines, which must appear first in the message.
YES | NO | ABSTAIN
Your Name <email@example.com>
After these five lines you can add an explanation of your
vote, if you desire. Providing the rationale for a NO vote
is particularly encouraged.
The voting period closes exactly two weeks after the time
that this message or any earlier valid YES vote on this proposal
was received by the png-list server (firstname.lastname@example.org)
You can change your vote by submitting a new message. Only
the last message sent by you and received by the png-list
server prior to the close of the voting period will be counted.
Your messages can be sent from different e-mail accounts, but
the fifth line of all of your messages, containing your name
and your preferred e-mail address, must be identical.
You are eligible to vote if your earliest message to png-list
was received at least 180 days earlier than the close of the
Contributors' names are presented in alphabetical order:
U.S. Army Research Laboratory
Aberdeen Proving Ground, MD 21005-5066
Phone: (410) 278-6554
EMail: email@example.com or firstname.lastname@example.org
End of PNG Chunk Registration Process document. Expires 26 Mar 1997.