Complex sentence: The "entry into the Pléiade" is considered a major sign of recognition for an author in France, and it is extremely rare that a living author is published in the "Pléiade" (examples are Nathalie Sarraute, Julien Green...).
Split into simpler sentences: The "entry into the Pléiade" is considered in France a major sign of recognition for an author. It is extremely rare that a living author is published in Pléiade (examples are Nathalie Sarraute, Julien Green...).