Rdoc, :"symbol", warning msg

Hello out there,

I have a statement that looks like this:

   when :foo, :"foo/", :"/foo", :"/foo/", :"foo/>", :"/foo>", :"/foo/>"

but rdoc barks on it:

lib/foo.rb:209:26: ':' not followed by identified or operator

even when I enclose this line in

# :stopdoc:
and
# :startdoc:

I get the same message. Could anybody help me getting rid of these
messages? I think that the when statement is valid, isn't it?

Patrick