Related Clues:

• Hint towards solution
• Aid to puzzlers
• Hint (for you?)
• (Some) indication
• This crossword structure
• Crossword constructor's "map"
• Lipstick print, maybe
• Unlocking aid
• Good riddance — ball's disappeared in grating
• 'Professor Plum in the library with the candlestick' game
• Network free after midnight
• Game played with a rope
• Network of spaced lines
• Game with Colonel Mustard
• Game that involves weapons