This one:
http://wiki.musicbrainz.org/HowToAddDiscIDs
(though you might say it is not a guideline)

If I am not mistaken, burning the exact same mp3 or whatever will result
in different discIDs dependent on the which burner one uses. Maybe even
with which program?

Thus, if we allow this, we will get hundreds of discIDs for some
releases, and most of these will only be useful to someone who happens
to burn their music in the exact same way on the same hardware as the
one who originally added the discID.

IMHO this is not useful, and we thus should not allow it as it does get
in the way. With which I mean that as we are displaying the release
events below the discIDs, having 100 or more of them on a release is not
very nice.

Bram / jongetje

Lukáš Lalinský schreef:

> Dňa Pi, 2008-05-09 o 21:07 +0800, Chad Wilson napísal:
>
>> BrianG has voted down an edit to remove a homeburnt disc ID at
>> http://musicbrainz.org/show/edit/?editid=8668756
>>
>> Since when has this practice changed, and is BrianG's position that the
>> practice should change technically defensible? (of course AutoEditors
>> voting against style guidelines isn't, in my opinion)
>>
>
> Which style guideline are you referring to in this case? I'm not aware
> of anything, and I personally dislike that removing these supposedly
> homeburnt discids became an accepted practice.
>
> Lukas

Couple of questions:

Does the identification of (alleged) CD-R copies work in both
directions? That is, if I put in a burnt CD, could my software (or the
MB API) be smart enough to say "that doesn't match any CD-Indexes of
official releases, but I'm 99% sure that it's a burnt copy of album
X". If people agree (as I do) that burning an album to CD shouldn't be
treated as some kind of crime in this era of the iTunes Store,
Creative Commons, and internet distribution etc. then this is a
valuable service to offer, and doing it pro grammatically makes more
sense than trying to get one CD-Index from every burner in the world.

If this CD-R identification method is fairly foolproof why isn't it
being done by an automated script? I'm guessing the people deleting
these are using a script to identify likely suspects to delete, what
extra human thought is added to the process that couldn't be
automated? And if we can automate this, why don't we just tag them as
"suspected home burnt CD-R" (possibly even link them to the original
they were copied from) and hide them from view instead of putting it
up for votes. In the standard case what can the voters possibly
contribute apart from confirming the +2 seconds algorithm has been
applied correctly? Sounds like a job for a computer to me.