Zettelkasten Best Practices

A reference guide for writing high-quality memex cards that compound in value over time. Covers card format, naming conventions, tagging, linking strategy, and graph health maintenance.

This is NOT a workflow skill (see memex-recall, memex-retro, memex-organize for those). This is a quality standard — consult it when writing or reviewing cards.

Card Quality Checklist

Before writing a card, verify:

• Atomic — one insight per card. If you can split it, do.
• Own words — distill and rephrase, don't copy-paste. This is the Feynman method: if you can't explain it simply, you don't understand it well enough.
• Non-obvious — would this change how you approach a similar task in the future? If not, skip it.
• Linked in context — [[wikilinks]] are embedded in sentences explaining why the relationship exists.

Card Format

---
title: "Short Noun Phrase ≤60 chars"
created: "YYYY-MM-DD"
source: "<auto-filled by client>"
tags: [domain-tag, type-tag]
category: "<domain>"
---

One atomic insight, written in your own words.

This relates to [[other-card]] because <explanation of the relationship>.

Required Frontmatter

Field	Required	Format
title	✅	Noun phrase, ≤60 chars
created	✅	ISO date YYYY-MM-DD
source	✅	Auto-filled by MCP/CLI client

Optional Frontmatter

Field	Format	Notes
tags	YAML list	See Tag System below
category	Single string	See Categories below
links	YAML list of slugs	Explicit links (in addition to wikilinks)
status	conflict / draft	Set by organize skill when needed

Body Rules

• Write in plain Markdown
• Use [[slug]] wikilinks inline, within natural sentences
• Keep cards concise — aim for a few paragraphs, not an essay
• Code examples are fine, but the insight should stand without them

Slug Naming

Slugs are permanent identifiers. Choose them carefully.

Format

• kebab-case, all lowercase English
• 3–60 characters
• Descriptive but concise

Examples

✅ Good	❌ Bad	Why
docker-compose-port-binding	note-1	Descriptive vs. meaningless
jwt-revocation-blacklist	docker	Specific vs. too broad
nextjs-app-router-caching	how-to-fix-the-bug-we-found	Noun phrase vs. sentence
vitest-mock-timer-gotcha	vitest_mock_timer	kebab-case vs. snake_case

Special Slug Prefixes

Use these prefixes to signal card type at a glance:

Prefix	Use	Example
adr-*	Architecture decision records	adr-monorepo-vs-polyrepo
gotcha-*	Pitfalls, traps, surprising behavior	gotcha-yaml-date-auto-parse
pattern-*	Reusable patterns, best practices	pattern-retry-with-backoff
tool-*	Tool-specific tips and configs	tool-gh-cli-pagination

These are conventions, not enforced constraints. Use them when they fit naturally.

Categories

Assign one category per card to indicate its domain:

architecture · backend · frontend · devops · tooling · security · workflow · testing · data

Categories are broad. Use tags for fine-grained classification.

Tag System

Tags serve two purposes: domain (what technology) and type (what kind of knowledge).

Domain Tags

Use the specific technology or concept name:

docker · nodejs · typescript · react · nextjs · postgres · redis · git · api · css · linux · aws · azure

Type Tags

Classify the kind of insight:

Tag	When to use
decision	A choice was made between alternatives
gotcha	Surprising behavior, easy-to-miss pitfall
pattern	Reusable solution or approach
howto	Step-by-step procedure
reference	Factual lookup (config format, API shape)
debug	Root cause analysis of a specific bug

Tagging Guidelines

• Use 1–3 tags per card (one domain + one type is ideal)
• Prefer existing tags over creating new ones
• Tags are lowercase, single-word or hyphenated (rate-limiting, not Rate Limiting)

Linking Strategy

Links are the most valuable part of a Zettelkasten. They create a network that surfaces unexpected connections.

Link in Context

Every [[wikilink]] should appear in a sentence that explains the relationship:

<!-- ✅ Good: link explains WHY -->
This contradicts what we found in [[jwt-migration]] — stateless tokens
can't be revoked without a server-side blacklist.

<!-- ❌ Bad: link without context -->
Related: [[jwt-migration]]

When to Link

• Contradiction — "This conflicts with [[X]] because..."
• Extension — "This builds on [[X]] by adding..."
• Example — "[[X]] is a concrete instance of this pattern"
• Alternative — "We chose this over the approach in [[X]] because..."
• Prerequisite — "Understanding [[X]] is necessary context for this"

Avoid Over-Linking

Not every card needs to link to every related card. Link when the connection would surprise someone or change how they read either card.

The Keyword Index

The index card is a curated entry point to the entire knowledge graph — inspired by Luhmann's Schlagwortregister (keyword register).

Purpose

• Provides structured entry points for the memex-recall skill
• Groups cards by concept, not by chronology
• Each card appears under 1–2 categories

Format

---
title: Keyword Index
created: <date>
source: organize
---

## Authentication
- [[jwt-revocation-blacklist]] — Server-side revocation for stateless tokens
- [[oauth2-pkce-flow]] — PKCE flow for public clients (SPAs, mobile)

## Docker
- [[docker-compose-port-binding]] — 0.0.0.0 vs 127.0.0.1 gotcha
- [[docker-multi-stage-builds]] — Reducing image size with build stages

The index is maintained by the memex-organize skill. You can also update it manually after writing cards.

The Recall → Work → Retro Loop

The core memex workflow is a learning cycle:

┌─────────────────────────────────────────────────┐
│                                                 │
│   ┌──────────┐    ┌──────────┐    ┌──────────┐ │
│   │  RECALL  │───▶│   WORK   │───▶│  RETRO   │ │
│   │          │    │          │    │          │ │
│   │ Search   │    │ Do the   │    │ Distill  │ │
│   │ existing │    │ actual   │    │ insights │ │
│   │ cards    │    │ task     │    │ to cards │ │
│   └──────────┘    └──────────┘    └──────────┘ │
│        ▲                               │       │
│        └───────────────────────────────┘       │
│              Cards feed future recalls          │
└─────────────────────────────────────────────────┘

• Recall (task start) — search for relevant prior knowledge before starting work. Avoid repeating past mistakes.
• Work — do the actual task, informed by what you recalled.
• Retro (task end) — reflect on what you learned. Write cards for non-obvious insights only.

This loop is implemented by the memex-recall and memex-retro skills. The key insight: retro is not just documentation — it's how you learn. Writing in your own words forces deeper understanding than simply bookmarking a Stack Overflow link.

Graph Health Maintenance

A knowledge graph degrades without maintenance. The memex-organize skill handles this, but here are the principles:

Orphan Cards (0 inbound links)

An orphan is a card that nothing links to. It may be:

• Genuinely standalone — fine, leave it alone
• Missing connections — search for related cards and add contextual links

Hub Cards (≥10 inbound links)

A hub card is referenced by many others. It may be:

• Appropriately central (e.g., a foundational concept) — fine
• Too broad — consider splitting into smaller, more atomic cards

Contradictions

When two cards disagree, this is valuable signal — not a bug. The organize skill flags contradictions with status: conflict for human resolution. Don't auto-resolve conflicting beliefs.

Staleness

If a card's information is outdated:

• Update it if the new info is a simple correction
• Write a new card + archive the old one if the new understanding is significantly different

Anti-Patterns

❌ Don't	✅ Do Instead
Write a card for every task	Only capture non-obvious insights
Copy-paste error messages as cards	Distill the root cause and fix
Create cards with no links	Always link to at least one related card
Use vague slugs like notes or misc	Use descriptive slugs: postgres-connection-pool-sizing
Write essay-length cards	Keep cards atomic — split if needed
Hoard tags (5+ per card)	Use 1–3 tags: one domain + one type
Link without explaining why	Every [[link]] needs a surrounding sentence

Quick Reference Card

For easy lookup, here's the complete format in one block:

---
title: "Descriptive Noun Phrase ≤60 chars"
created: "2025-01-15"
source: "<auto>"
tags: [typescript, gotcha]
category: "backend"
---

<One atomic insight in your own words.>

<Context with [[wikilinks]] explaining relationships.>

Slug: kebab-case-english-3-to-60-chars Tags: 1 domain + 1 type, lowercase Links: in sentences, not in lists Length: a few paragraphs, not an essay