1-9 may refer to: 0s, the first "decade" of the AD/CE time system (AD 1–9) 1% rule (Internet culture), also known as the 1–9–90 rule Two services of the New York City Subway which formerly ran together 1 (New York City Subway service) 9 (New York City Subway service) U.S. Route 1/9 concurrency in northern New Jersey Emergency telephone number for city police in Morocco See also 1/9 (disambiguation)