Broader than you might think
If you mouse over the board title you will see the guidelines.
Acceptable topics include anything aviation, space or tech, past present and future, including fiction.
The main things unacceptable are posts asserting the reality of anomalies and bogus science.
In other words, we don't mind laughing at Nessie but don't assert that Nessie is real.
We love scifi but don't present it as a current event or a history lesson.