Marginalia (noun)

1. Notes, comments, or drawings written or made in the margins of a book or document.
2. Miscellaneous or supplementary material, especially in a book or publication.
3. Minor or secondary items or details.

Origin:

The word marginalia comes from the latin word "marginalis," meaning of or belonging to the margin.

Examples:

1. The marginalia in the old manuscript included commentary and sketches by the author.
2. The book's marginalia contained interesting tidbits of information that were not included in the main text.
3. The marginalia of the budget proposal were carefully analyzed to see if any expenses could be trimmed.
4. The marginalia of the scientific paper were filled with suggestions for future research.
5. The marginalia of the agreement spelled out the details of the implementation plan.