Departure procedures are published IFR procedures from the terminal area to the appropriate en route structure. The primary reason they are established is to provide obstacle clearance protection. At busier airports they also increase efficiency and reduce communication and departure delays. If an airport has non-standard take off minimums and/or departure procedures are published for the airport, a black triangle with a T inside it will be placed in the notes section of the instrument procedure chart. To determine takeoff minimums for IFR flight when there is no published DP, it is good operating practice to use the minimums listed in the approach procedure for that airport. If no approach procedure is available, basic VFR minimums are recommended (1000 feet and 3 miles). There are two types of DP’s: Obstacle Departure Procedures (ODP’s) and Standard Instrument Departures (SID’s).