Tips for Improving Writing Rules in Claude Code

When using Claude Code, if writing style rules are placed in CLAUDE.md, the model tends to recognize them as context and process them selectively. To resolve this, it is recommended to use Output Style Files.

Advantages of Output Style Files

Output style files are located in the system prompt and reinforced every turn, preventing the model from ignoring instructions or experiencing style drift.

Setup Method

1. Create a .md file in the ~/.claude/output-styles/ directory.
2. Specify keep-coding-instructions: true in the frontmatter at the top of the file. Without this option, existing coding instructions may be overwritten.
3. Define specific writing rules in the file content, such as using concise declarative sentences, prohibiting first-person pronouns, and prohibiting unnecessary additional explanations.
4. Restart Claude Code and select the style in the settings.