y and XML file
formats but all have the above interface.  Given that all archives present
the same public interface, specifcation of serialization is exactly the same
for all archives.  Archive classes have other members not mentioned here.
However they are related to the internal functioning of the library and
are not meant to be called by users of an archive.  Implementation of new
archives is discussed in 
<a href="archive_reference.html#implementation">New Archives - Implementation</a>.

<p>
The existen