Norm ISO 5807 :

Any part of treatment: execution of an action, of a sequence (group of actions) to modify the value or the shape or the position of information.

Subroutine call.

Treatment executed by a human operator: action on a button, for example.

Action to prepare an ulterior activity, for example the pins configuration (input/ouput), the modification of an index register or the routine initialization.

Function type selection or decision wich includes only one input and two possible outputs. It can be activated (YES output) after the assessment of a conditional expression defined in the symbol.

Symbol in two parts representing the beginning and the end of an iteration (loop).

The two parts of the symbol have a common identifier.

Conditions of initialization, incrementation and completion, etc., are in the beginning symbol.

Output toward the outside, input from the outside, for example the beginning or the end of a program, a subroutine or an external use : the origin or the destination of data.

Addition, for clarification, of descriptive commentaries or explanatory notes.

Lines of text are joined to the symbol concerned by an interrupted feature.