IAP charts are aeronautical charts that portray the aeronautical data that is required to execute an instrument approach to an airport. Besides depicting topographic features, hazards and obstructions, they depict the procedures and airport diagram. Each procedure chart uses a specific type of electronic navigation system such as an NDB, TACAN, VOR, ILS/MLS and RNAV. The chart name reflects the primary navigational aid (NAVAID), if there is more than one straight-in procedure or if it is just a circling-only procedure. A communication strip on the chart lists frequencies in the order they are used. Minimum, maximum and mandatory altitudes are depicted in addition to the minimum safe altitude (MSA) for emergencies. A cross depicts the final approach fix (FAF) altitude on NPAs while a lightning bolt does the same for PAs. NPAs depict the MDA while a PA shows both the decision altitude (DA) and decision height (DH). Finally, the chart depicts the missed approach procedures in plan and profile view, besides listing the steps in sequence.