# GitHub Copilot Instructions

**Never use the unicode multiplication symbol (×, U+00D7) in any documentation, code, or markdown.**

Always use a plain lowercase 'x' for dimensions and multiplication.

- WRONG: `25mm × 25mm × 25mm`
- CORRECT: `25mm x 25mm x 25mm`

# Wiki Tagging Rules

All challenge pages in the wiki must include YAML front matter with a `tags` list.

## Tagging Standards

1. **Challenge Tag**: All challenge pages must have the `challenge` tag.
2. **Number Tag**: All challenge pages must have a sequential number tag in the format `challenge-XXX`.
   - `challenge-001`: October 2025
   - `challenge-002`: November 2025
   - `challenge-003`: December 2025
   - Increment for subsequent months.
3. **Archive Tag**: Past challenges must have the `archive` tag.

## Example Front Matter

```yaml
---
tags:
 - challenge
 - challenge-002
---
```