YAML / Front matter / Properties (Obsidian)

For tools like Obsidian, there is an option to write metadata that applies to the whole content of the note in a section that is called front matter.

Obsidian opted to use YAML, which is a recursive acronym for “YAML A'int Markup Language” (documentation here: The Official YAML Web Site) and due to that, this section is also known by its users as YAML. YAML and the note front matter are not the same thing, but for practical purposes, there is no need for nitpicking.

In more recent versions, Obsidian started calling these “properties”, and implemented a GUI to view and edit them. There are some particularities with property types to consider, and a special attention is required about the date formats used.

The front matter must be at the top of a note, starting with three dashes (“-”), and ending with another set of three dashes.

---
author: Jorge Godoy
date: 2023-01-02
tags: 
    - documentation
    - study
---

For items with multiple values, the syntax of the example above (multiple lines, starting with spaces and a hyphen) is preferred over using arrays ([item1, item2]). This has been standardized like that in GitHub - obsidianmd/obsidian-api: Type definitions for the latest Obsidian API., and more and more plugins should use it to address metadata at this section of the note.

One important thing here: by default – without plugins extending it – Obsidian do not support links at the front matter. If you link to another note, for example, this information won't be updated here as it would be in the body of the note. ^[1]

Properties usage examples

Properties are used to classify information, add date details, provide additional links that aren't present in the text of your note (or that also appears at the text of your note), geolocation information, etc.

“Databases” and properties

After Obsidian 1.9, properties can also be used with the core plugin Bases. With that you can use your notes as if they were entries in a database. And, then, your properties become you columns and the value for each column is the value of the property for that column.