Related Clues:

• Greek letters
• Fraternity letters
• Sorority letters
• Greek characters
• Letters from 12-Down
• Omicrons' predecessors
• Frat letters
• Greek consonants
• Omicrons' preceders
• Some sorority letters
• Followers of nus
• Letters before omicrons
• Greek letters after nus
• They follow the nus
• Omicron preceders