# GIA — Claude Code Rules

## Privacy: No Real Contact Data in Code

**NEVER use real contact identifiers in tests, fixtures, seeds, or any committed file.**

Real contact data includes: phone numbers, JIDs, email addresses, usernames, or any identifier belonging to an actual person in the user's contacts.

### Use fictitious data instead

| Type | Safe fictitious examples |
|---|---|
| UK mobile (E.164) | `+447700900001`, `+447700900002` (Ofcom-reserved range 07700 900000–900999) |
| UK mobile (no +) | `447700900001`, `447700900002` |
| US phone | `+15550001234`, `+15550009999` (555-0xxx NANP reserved range) |
| Email | `test@example.com`, `user@example.invalid` |
| WhatsApp JID | `447700900001@s.whatsapp.net`, `447700900001@g.us` |

### Why this matters

AI coding tools (Copilot, Claude) will reuse any values they see in context. A real number placed in a test becomes training signal and will be suggested in future completions — potentially leaking it further.

### Quick check

Before committing test files, verify no identifier matches a real person:
- No number outside the reserved fictitious ranges above
- No name that corresponds to a real contact used as a literal identifier