Why Nested Tags Are Not That Good
A common pattern I often see is the use of nested tags, written in a hierarchy like #thing/subthing. In theory, this allows you to create categories and subcategories.
The problem is that, over time, hierarchies can become arbitrary. What once made sense as #thing/subthing might later feel more natural as #subthing/thing. Or you might end up with variations like #other/thing and #other/subthing.
At first glance, this doesn’t seem like an issue: you can just create new tags and move on. But when it comes to searching and querying, nested tags quickly become limiting. For example, you can’t simply query subthing; you must query the full hierarchy, which adds complexity.
The Case for Flat Tags
Using flat tags like #thing, #subthing, and #other provides far more flexibility. You can query individual tags regardless of their combinations, and by requiring two or more tags together, you can replicate the specificity of nested tags without the rigidity.
Examples:
- Instead of
#medicine/drugsand#studies/medicine, use#medicine+#drugsor#studies. - Instead of
#work/traveland#personal/travel, use#work+#travelor#personal+#travel. - Instead of
#work/meetings,#church/meetings, and#family/meetings, use#meetingscombined with#work,#church, or#family.
Flat tags automatically create more combinations and allow you to slice your data in multiple ways, making your vault more adaptable over time.
But…
Nested tags are not inherently “bad.” If you plan carefully, review your taxonomy regularly, and are comfortable with more complex queries, they can work. Some people prefer the visual hierarchy they provide.
However, if your workflow relies heavily on search and flexibility (as mine does), nested tags can become a constant source of friction.
The key is to assess your use cases and document your tagging strategy. This helps prevent creating multiple permutations of the same hierarchy by mistake and ensures your system remains consistent.
Conclusion
Nested tags may look neat at first, but they often lock you into rigid structures that don’t age well. Flat tags, on the other hand, give you freedom: you can combine them in endless ways, adapt as your needs evolve, and keep your vault flexible.
In the end, the best approach is the one that aligns with your workflow, but if search and adaptability matter to you, flat tags will serve you better.