There are various problems with making a distinction
between print and
online use when it comes to name inclusion. The first problem is that
there are related questions which immediately pop up: Is it reasonable
for a one page print document to have half a page or more of author
metadata? Is it reasonable for a t-shirt to have to include a metadata
text-block? Is a DVD substantially different from a print product? Is
a screen in a flight information system? So in order to deal with
those cases, you start making more complex rules which, again,
discourage meaningful re-use. This in spite of the fact that the
usernames we are talking about, in a large number of cases, will only
be unambiguous and meaningful if resolved to username URIs; the extent
of their contributions can only be meaningfully ascertained when
reviewing a page history.
A lot of the problems you are having there are because you are trying
to group things into "print" and "online". The correct dichotomy is
"online" and "offline". Of course you are going to have problems
classifying DVDs if your classifaction systems assumes all electronic
data is only available on the internet. I don't see a problem with
listing authors in fairly small print on the back of a t-shirt, seems
perfectly reasonable to me. If instead of names there's just a URL on
the t-shirt, does that mean I can't where it in China since people
seeing it won't have any way (without significant technical know-how)
to view the list of authors?
People choosing to submit work under a pseudonym have clearly
indicated that they are happen to be attributed under that pseudonym,
I don't see any need to provide context. (It's good to do so where
practical, of course.)