| Clue | Source | Date |
|---|---|---|
| 'The first thing you must know ... ' | ||
| "The first thing you must know ... " | LA Times Daily | 03 Jun 2018 |
| Prime directive | New York Times | 09 May 2018 |
| "The first thing you must know ... " | ||
| Prime directive | ||
| For Fight Club, it's 'You do not talk about Fight Club' | Wall Street Journal | 13 Jul 2017 |
| Principal principle | ||
| The primary instruction | ||
| The most important principle | ||
| The first requirement | ||
| Most important guideline | ||
| The first requirement | ||
| Starting guide | ||
| "You do not talk about Fight Club" for "Fight Club," e.g. |