subspecialized

Verb

subspecialize (third-person singular simple present subspecializes, present participle subspecializing, simple past and past participle subspecialized)

1. To specialize within a particular area of a specialty.
   • Although most collectors subspecialize by genre, whether jazz or classical or country, it’s early American rural blues — loose acoustic laments, recorded before 1935 and performed by artists who were born in or near the Mississippi Delta — that inspires the highest prices and the most fevered...2009 July 12, Amanda Petrusich, “They’ve Got Those Old, Hard-to-Find Blues”, in New York Times