[boost] What does a milestone of "release" mean?

Looking at http://svn.boost.org/trac/boost/report/3 We have a large number of reports with a milestone of "release" whatever that may be ! Many of these appear to be old, and/or no longer relevant, looks like these need triaging and either assigning to 1.35 or "To be determined" (or whatever we call it). John.