Transitional/dummy packages unhelpfully shown by default

That seems like a good idea. Two questions:
1. How can we tell, programmatically, which packages are transitional?
2. Who would ever want to see transitional packages, and when?

An answer to my first question:

<mpt> If anyone knows how a computer program can tell the difference between a transitional Ubuntu package and a non-transitional one, please let us know in bug 526330
...
<seb128> mpt, it can't really I think
...
<seb128> mpt, seems we would need to add extra informations in the system somewhat
...
<mpt> seb128, how about "Depends on one other package and contains no files itself"?
<seb128> mpt, those have files, ie copyright, etc
...
<chrisccoulson> "no files itself" is normally incorrect
<mvo> mpt: not trivially, there is a idea to add a "transitional" section that would solve it nicely
<chrisccoulson> yeah ;)
<seb128> so it would be "no file out of the standard ones"
<seb128> but they are not the only one in this case
...
<mvo> and we don't know the filelist until we downloaded it
<seb128> like we have common packages stripped from translations matching as well
...
<mpt> mvo, is anyone/anything tracking the progress of the "transitional" section idea?
<Laney> there's a lintian tag empty-binary-package
<Laney> you could look how that works
<Laney> I think it looks at the description to decide to exclude transitional packages, so inverting that logic could fly
<mvo> mpt: not currently :( its something that ideally would be part of the debian policy and is useful for other things (like automatic dependency tracking). the best way forward is probably to start a discussion on debian-devel

If anyone gets this organized, please reassign back to me for design work. In the meantime, an answer to my second question would still be useful: Who would ever want to see transitional packages, and when?

The only time I can think of caring about transitional packages is when they suddenly become nontransitional due to naming conflicts with a PPA.

As an update, we have now standardized on putting transitional packages into the "oldlibs" section. Would it be wise to just hide everything there by default? (do we do this already?)