Mostly considering what it says when you hover over "Contact Guildmasters".
All joking aside, in order to participate in Guild Events you must be part of a Guild. We have however a proposal for a Patch system which much like MMORPGs will allow us to release Guilds in a certain form at first and, should it require modifications, will receive routine patches with 1-2 weeks notice provided for upcoming changes.
Ultimately, Guilds will take the form of how the majority of the community want them to be, but this will take input, patience and above all, understanding.