Promotion/relegation next season-- BBC Sport article
Formed in 1990, the Principality Premiership has had nine different winners, the most successful of which is Neath with seven titles
Welsh rugby's Premiership is set to have its numbers reduced from 16 to 12 from the 2019-20 season.
New regional under-23 sides will also be introduced to bridge the gap between the Premiership and the Pro 14.
The Welsh Rugby Union declined to make any comment however their Competition Review Group will meet later this week to discuss the plans further.
The plans for the new U23 sides consist of roughly 10 games, including cross-border matches.
At the end of next season, the Premiership's lowest four clubs will be relegated while the fifth-lowest club will have a play-off with the Championship's winners for a place in the top flight.
No team in the Premiership is protected from this relegation including the likes of RGC 1404 and regional sides such as Cardiff, Newport and Swansea.
After the reshuffle, continued promotion and relegation between the Premiership and Championship would be put in place.
The new model also makes no exceptions for club's alignment with regional teams. Should a region lose all representation in the Premiership it will remain that way until another is promoted.
Additional funding is to be provided to Championship clubs under the new model to allow them to be more competitive.
No clear costs for the reshuffle have been given however BBC Sport Wales understands the funding for the first season would remain the same before being reduced in the following seasons.
Similar Under-23s plans have been put in place in Ireland and Scotland since news that the British and Irish Cup would be scrapped from next season.
Fixtures for the new league are expected to be split into two blocks, one before and one after the Six Nations.
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