(still off topic! sorry!)
In fact, the US Copyright law seems to need only
the first year of publication:
http://www.copyright.gov/circs/circ1.html#fnv
but I guess we want to be really conservative
across countries and their laws on copyright.
Actually even the first year is not required. Look at the paragraph above
the one you quote, which clearly says that no notice is required (this
is one of the big [and unfortunate] changes in US copyright law that
has occurred recently. It is still a good idea to have the notice since
as the quoted text notes, this can help defuse the "innocent
infringement" defence.)
An entertaining anecdote. At lunch with a faculty candidate I noted that
copyright notices were no longer required and served no useful
purpose. The candidate disagreed and had the following interesting
story, she had come out of a bad relationship and was depressed
and so threw herself into work furiously. Every day she was using
a software package that said "copyright bla bla", and the bla bla was
someone she knew from graduate school. Finally the reminder prompted
her to give him a call, and at the time we talked they had been living
together for a while.
So she said "don't tell me that copyright notices are useless" :-)
