Blank Betting Slip is a written note found in Death of the Outsider.
Transcript[]
Albarca Betting
Fighter _ _ _ _ _ _ _ _ _
Time & Match _ _ _ _ _ _ _ _ _
Stake _ _ _ _ _ _ _ _ _
All bets by house rules
Location[]
This note can be found on the bookmaker's counter in the Albarca Baths during the mission One Last Fight.