worthy of special mention; notable; remarkable
Used as a prenominal modifier (e.g., 特筆すべき点) to highlight something that deserves particular attention or praise.
His research has several notable achievements.
What is particularly noteworthy at this year's tournament is the performance of the young athletes.
Compound of 特筆 (special mention) + すべき (should do), from classical すべし. The phrase is a fixed expression meaning 'should be specially noted'.