Backward compatibility in Domino R8?

Is there any document which explains about backward compatibility within Domino R8.Is there 100% backward compatibility in R8 with lower version of Lotus Domino versions like R6.5? or is there anything which is not supported in Domino R8, but works fine R6 versions?

Please suggest.

Vishal.

Subject: Backward compatibility in Domino R8 ??

Should be completely backward compatible, less any regression bugs. I don’t know of any documentation.