Related Clues:

• Part of a footnote abbr.
• Op. ___
• Native: Abbr.
• Op ___
• Op. ___ (footnote abbr.)
• Loc. ___
• Summons: Abbr.
• Op ___ (footnote abbr.)
• Op. ___ (in the work cited)
• Op. __
• Camp apprentice, for short
• Camp supervisor-to-be, briefly
• Op ___ (in the work cited)
• Footnote abbr., op. ___
• Op. --. (where mentioned)