Conduct yourself properly.
Don't do things that would endanger the forum.
More specific stuff:
No Sharing, promoting or distributing materials related to Terrorism or hate speech.
No Posting, transmitting, re-transmitting, or storing material that violates any law or regulation of The United States, Germany, Finland, Netherlands, including copyrighted materials, trade secret, patent, or other intellectual property laws.
No Posting or transmitting illegal, threatening, obscene, or defamatory content.
No mentioning websites associated with hacks or cheats.
No Illegal stuff.