The three letters you see above players are the guild's tag
+3.5% experience bonus when 10 or more players online in the guild
+15% loot bonus when warmode is enabled
Emblems
Blue: The player you are seeing is in a neutral guild.
Green: You or the guildmate is in a neutral guild.
Purple: You or the guildmate is in warmode.
Red: The player you are seeing is in warmode.
Guild leader: Use commands !warmode start/end to enable/disable warmode after next serversave. Players in a guild with warmode does not gain unjustified kills or skull when attacking another player in a guild with warmode. It triggers after next server save.
At each unlock level, you can only pick one of the two buffs. As a guild leader you can change the buff every hour. Values below are shown as Tier 1 / Tier 2 / Tier 3. Tier 1 applies through guild level 21, Tier 2 at levels 22-23, and Tier 3 from level 24.