General guidelines

Text format

  • Set the font to Open Sans. If your tool does not have Open Sans, set the font to a different sans serif font, like Helvetica.

  • Set the font size to at least 6px or above.

  • All objects must be labeled with text.


  • An object must be a closed geometric shape or icon.

  • Objects must have a hollow middle, where text can be added.

  • All objects must be labeled according to their function.

Object color

Any objects inside a diagram should be black, unless the object needs to be emphasized within a diagram in order to fully understand its function. Colored objects may only use bright primary colors, such as light blue, red, or green. You can make multiple objects the same color, provided the objects serve similar functions or purposes.


  • Set line width to at least 2px or above.

  • Avoid crossing an object with a line.

The following are recommendations for line shape and usage.

Line shape

Keep lines straight unless a line needs to change direction. If a line changes direction to reach an object, the corner in which the change of direction occurs must be rounded.

Solid lines

Use solid lines to show a direct relationship between objects. For example, objects within a reference architecture that are used in conjunction with each other.

Dashed lines

Use dashed lines to group objects connected through an online network. For example, an object that uses neutron to connect to a server.

Dotted lines

Use dotted lines to show how data entered by a human user travels.


Use arrows to represent one-way interactions between two or more objects. If an object is attached to an arrow, it implies that the function represented by the object can only work when interacting with another object in the diagram.