3.3 — Path-Specific Rules for Conditional Convention Loading

CCAR-F Domain 3 · Task 3.3

What You Need to Know

Path-specific rules load conventions only when you edit files matching their glob patterns. They solve what neither root CLAUDE.md nor directory-level CLAUDE.md handles well: one file type scattered across many directories.

How Path-Specific Rules Work

Rule files live in .claude/rules/. Each starts with YAML frontmatter:

---
paths: ["terraform/**/*"]
---
# Terraform Conventions
- Use snake_case for all resource names
- Tag every resource with environment and team labels

Why Not Directory-Level CLAUDE.md?

Test files across 50+ directories would need a CLAUDE.md in each → massive duplication and drift.

Why Not Root CLAUDE.md?

Root CLAUDE.md loads in every session. Terraform conventions would consume tokens while editing React components.

Key Concept: Path-scoped rules are more token-efficient because they load only when you edit matching files.

When to Use Each Approach

Scenario	Best approach
Universal team standards	Root CLAUDE.md
Conventions for one package directory	Directory-level CLAUDE.md
Conventions for a file type across many directories	Path-specific rules with globs
Task-specific workflows on demand	Skills

Exam Traps

• Choosing directory-level CLAUDE.md for cross-directory conventions
• Placing file-type-specific conventions in root CLAUDE.md
• Confusing skills with path-specific rules for automatic convention application