text: * ISO 15519-1:2010(en): Specification for diagrams for process industry — Part 1: General rules
  * ISO 15519-2:2015(en): Specifications for diagrams for process industry — Part 2: Measurement and control
  * ISO 10628-1:2014(en): Diagrams for the chemical and petrochemical industry — Part 1: Specification of diagrams
  * ISO 10628-2:2012(en): Diagrams for the chemical and petrochemical industry — Part 2: Graphical symbols
  * ANSI Y32.11: Graphical Symbols For Process Flow Diagrams (withdrawn 2003)
  * SAA AS 1109: Graphical Symbols For Process Flow Diagrams For The Food Industry