The clue for 28ac in yesterday’s Times Crossword 27,616 was: “I’ll represent head of faculty on stage to provide clarity” (10).
The definition is “clarity” in the wordplay, “faculty” leads to “ability”. Its first letter (“head”) is replaced with I (“I’ll represent”). This comes after (“on”) LEG, meaning “stage” (as, for example, a stage of a race). Putting it all together, you get LEGIBILITY.