Tags

Tags in Notarium are a full-fledged axis of navigation, not just labels on cards. You set them in a note's frontmatter, and Notarium turns them into a facet filter: one click narrows the Feed or the Graph down to the topic you want. Tags are hierarchical (via /) and case-insensitive.

How to set tags

Tags live in a note's frontmatter — the ordinary YAML block at the top of the file:

---
title: Notes on transformers
tags: [ml/nlp, reading]
---

Note body…

Hierarchy is expressed with /: ml/nlp is the tag nlp inside ml. Case doesn't matter — ML and ml count as one tag.

Hierarchy and filtering

The key property of the hierarchy is that a parent includes its children. Filtering by ml shows notes tagged ml, ml/nlp, and ml/cv alike. That lets you keep tags as fine-grained as you find convenient without losing the ability to view a topic as a whole.

The filter works as a union (OR): select several tags and the selection widens — notes matching any of them show up. Select nothing and there's no filter.

The filter widget speaks the same language in two places:

• In the Feed — a tag panel next to folders and text search. Tags are part of the URL, so a filtered view can be bookmarked or shared. The Feed's window, counter, and date histogram describe exactly the filtered selection.
• In the Graph — the same hierarchical chips plus an All / Tagged / Untagged toggle.

Tag chips in the reader header and the metadata panel are links: clicking one opens the Feed filtered by that tag. On Feed cards the tag chip is part of the card itself: clicking it (the chip included) opens the note rather than the tag-filtered Feed.