There are 3 main Ranks inside a guild:  Boss, Assitant and Member. 

The guild Boss can appoint several Assistants among other guild memebers.

Only the Boss and Assistants have the ability to manage the guild, they can:

• Rename the guild;
• Change the guild's privacy settings (public or private);
• Change the minimum joining level;
• Choose a building for investment discount;
• Dismiss a member from the guild;
• Send invitations to other players.