claude-code-plugins / rules

---
description: Prevent content duplication in documentation, reports, and code. Check for existing content before creating new. Consolidate duplicates to single source of truth.
alwaysApply: true
---

# Anti-Duplication Rule

## Core Principle

**Every piece of information should exist in EXACTLY ONE authoritative location.** All other references should link to that location.

## Before Creating Content

1. **Search first**: Does this content already exist?
2. **If similar content exists**: Link to it, update it, or consolidate - don't duplicate
3. **If truly new**: Create in ONE canonical location, link from elsewhere

## Common Scenarios

### Multiple Reports on Same Topic

**Wrong**: Separate files for findings, analysis, verification, summary

**Right**: ONE comprehensive report with sections for each

### Documentation in Multiple Files

**Wrong**: Same setup instructions in README.md and docs/setup.md

**Right**: Complete instructions in one file, link from the other

### Version/Config Info Scattered

**Wrong**: Version "2.0.0" mentioned in 4 different files

**Right**: Version in ONE canonical location, all others link to it

### Configuration Examples

**Wrong**: Same config example copied into 3+ files

**Right**: ONE canonical example, all others link to it

## Detection Questions

Before creating content, ask:

1. Have I seen this information before in this repo?
2. Is there an existing file covering this topic?
3. Am I about to copy-paste from another file?
4. Could this be a link instead of duplicate text?

If YES to any: **STOP, SEARCH, CONSOLIDATE**

## Progressive Disclosure Pattern

```text
main.md (Entry Point)
├─ Brief overview
├─ Quick reference
└─ Links to detailed guides

guide-1.md (Detail) - Complete details on topic 1
guide-2.md (Detail) - Complete details on topic 2
```

- Entry point: Overview + links (no duplicate content from details)
- Detail files: Complete information (each topic in exactly ONE file)

## When Duplication is Found

1. Identify all instances
2. Choose canonical location
3. Consolidate to that ONE location
4. Replace duplicates with links
5. Verify links work

## Golden Rule

**Link, don't duplicate.**

If information must appear in multiple places: store it ONCE, link from everywhere else.