10 Dec, 12:23
Ireland's John Lacey will referee his first ever RBS 6 Nations while Alain Rolland is also included in the Elite Panel in what is his last season.
For Ulster it will be their first opportunity to compete for the title through a play-off, having last taken the league crown in 2006.
In the three previous play-off finals the top seeds have become champions just once, when Munster defeated Leinster 19-9 at Thomond Park in 2011.
In the other two finals, both held at the RDS, that season's top seeds Leinster were defeated by the second-placed team, the Ospreys. No team that finished lower than second in the table during the regular season has ever lifted the title.
RABODIRECT PRO12 FINAL:
Saturday, May 25 -
ULSTER (1st) v LEINSTER (2nd), the RDS, 4.45pm (live BBC 2 Northern Ireland/TG4/RTÉ Two/BBC ALBA/BBC 2 Wales/SportItalia 2)