Possible Clues:

• Some sons: abbr.
• III preceders: Abbr.
• Sammy Davis and Cal Ripken: Abbr.
• High school yearbook sect.
• Between sophs and srs
• Next year's grads
• 11th graders: Abbr.
• Some 5-Down takers
• Eleventh-grdrs.
• Some namesakes, for short