# [[Structure Notes]]
Structure notes, or structure zettel, are elements of a [[Zettelkasten]] [[Personal Knowledge Management|PKM]] system that introduce a topical hierarchy to organize zettels into.
Structure notes are similar to the idea of a [[Map of Content]], although an MoC has a connotation of operating only on the top level. Structure notes can be used to simply group a bunch of related notes together, even if it's not a zoomed-out topic itself.
Ideally, structure notes would be created after clusters of notes organically form around a topic. However, the biggest problem with structure notes is that it can be difficult to identify these clusters. Graph views from the likes of [[Obsidian]] and [[Roam Research]] (although Roam's is pretty basic) may help to highlight these clusters. Another effective technique may be a weekly or regular review of maps of content.
## Implementations
- In [[Zettelkasten]], Luhmann used Hub notes
- [[Nick Milo]] talks about using a [[Map of Content]].