The short version: Be excellent to one another.
"Our group is dedicated to providing a harassment-free event experience for everyone, regardless of gender, gender identity and expression, age, sexual orientation, disability, physical appearance, body size, race, ethnicity, or religion (or lack thereof).
We do not tolerate harassment of group participants in any form. Sexual language and imagery is not appropriate for any meetup venue, including talks, workshops, parties, Twitter and other online media. Group participants violating these rules may be sanctioned or expelled from the group (without a refund if applicable) at the discretion of the group organisers."
The long version is at confcodeofconduct.com which is also the source for the above.
Any donation buys you the warm feeling that you've helped make each iNOG happen.
You really get nothing else, no preferential treatment, no guarantee of talks, just warm and fuzzies. Close to 50 hours of unpaid planning, meetings, testing, hosting, web/video/copy editing and design, marketing etc. goes in to each iNOG. Donations will help fund swag, stickers, and behind the scenes sunk costs such as; hosting, SaaS subscriptions, meetings, planning, feeding volunteers, and enabling organisers to continue to contribute professional time. iNOG has no funding and is not registered as a charity, non-profit, or designated activity group *yet* so, this is currently facilitated via Defensible Limited.