Marginal Notes
A.k.a. Side Notes
The term "marginalia" or "marginal notes" is derived from the latin word "margo", which means "margin" or "boundary".
Marginal notes are side notes that are placed in the margin of a text, usually in a smaller font size.
Unlike footnotes, marginal notes do NOT belong to the type area!
Marginalia are used to give a quick overview of the aside text components, using keywords. The first line of the marginal note must be in the same line as the corresponding text component.
Due to the fact that these notes take up quite some space, the outer margin must be sufficiently wide, and you should clarify before designing the type area, whether marginal notes are going to be used or not.
It is recommended to set the aside main text to justified alignment.