Guilds help to coordinate your army's actions. Each guild can have up to 100 members, and needs at least 5 guild members to be listed in Guild List page.
You can join only one guild at a time. Whenever you post a Call To Arms (CTA) or request for Elite Guard, this is also posted in your Guild's feeds. Other than the Feeds tab, there are also General, Monster, Battle, Quest tabs (where Urls and Links are stripped out for security purposes). For Monster and Battle tabs, the new features which will be coming out soon are Top Monster Contributors and Top Battle Contributors.
To join another Guild member's Elite Guard, you need to be in the same army. Guild members that are not in your army have an "add" image next to their name. Guild members that are in your army have a white envelope next to their name for messaging purposes.
There are also two "coming soon" features on the Guild's main page: Guild Achievements and a link to the Guild Leaderboard.
There are five guild standards or banners:
Invites & Control Panel
Only Guild Master and Officers have access to this Control Panel. Guild Master and Officers also have the access to pending guild requests and guild request invites.
The Guild List page listed all the guild names, their standard/banner and number of members. You can also use the view button to view the guilds and their members.