Chreia or Khreiai

"Chreia" (from the Greek chreiodes, "useful") is "a brief reminiscence referring to some person in a pithy form for the purpose of edification."

The chreia (χρεία or chria) was, in antiquity and the Byzantine Empire, both a genre of literature and one of the progymnasmata.

An elementary exercise, or progymnasmata, in which the speaker or writer comments briefly on a famous event or saying.

Preliminary rhetorical exercises that introduce students to basic rhetorical concepts and strategies.

In classical rhetorical training, the progymnasmata were "structured so that the student moved from strict imitation to a more artistic melding of the often disparate concerns of speaker, subject, and audience" (Encyclopedia of Rhetoric and Composition, 1996).

The Exercises
This list of 14 exercises is drawn from the progymnasmata handbook written by Aphthonius of Antioch, a fourth century rhetorician.

1-fable
2-narrative
3-anecdote (chreia)
4-proverb (maxim)
5-refutation
6-confirmation
7-commonplace
8-encomium
9-invective
10-comparison (syncrisis)
11-characterization (impersonation or ethopoeia)
12-description (ekphrasis)
13-thesis (theme)
14-defend/attack a law (deliberation)

h/t - Nicrap