From the Burning Man website:

What is Burning Man?

A city in the desert. A culture of possibility. A network of dreamers and doers.

Once a year, tens of thousands of people gather in Nevada’s Black Rock Desert to create Black Rock City, a temporary metropolis dedicated to community, art, self-expression, and self-reliance. In this crucible of creativity, all are welcome.

Burning Man isn’t your usual festival. It’s a vibrant participatory metropolis generated by its citizens.

 
The 10 Principles of Burning Man
Burning Man co-founder Larry Harvey wrote the Ten Principles in 2004 as guidelines for the newly-formed Regional Network. They were crafted not as a dictate of how people should be and act, but as a reflection of the community’s ethos and culture as it had rganically developed since the event’s inception.

Radical Inclusion
Gifting
Decommodification
Radical Self-reliance
Radical Self-expression
Communal Effort
Civic Responsibility
Leaving No Trace
Participation
Immediacy

Read full descriptions of the Principles here.

Burning Man website