In the SAFe work item hierarchy, Features are decomposed into what?

In the SAFe work item hierarchy, Features are indeed decomposed into Stories. This is supported by

the information found in the SAFe Requirements Model, which outlines that a Feature is described

by a phrase, benefit hypothesis, and acceptance criteria, while a Story is elaborated by a user-voice

statement and acceptance criteria. These artifacts replace the traditional system and requirements

specifications with new paradigms based on Lean-Agile development. Stories are the primary artifact

used to define system behavior in Agile and are short, simple descriptions of functionality told from

the user’s perspective and written in their language. Each implements a small, vertical slice of

system behavior. The detailed implementation work is expressed through stories, which comprise

the Team Backlog12.