Just an idea for an item that guilds could use for their own events, similar to the ‘lost coins or badges’ in Silverwastes and Dry Top.
This could be in the form of a small Guild coin or a smaller version of a guild banner.
Just something that could be hidden by players themselves to create a small event for their guild.
These items would be invisible to everyone except the person hiding them until the event is activated, and then only visible to guild members.
There could be a Guild NPC to start the event and also for players to hand their coins/banners into, maybe even with a score table of who in the guild is currently winning.
The event could be time limited, say for example items disappear after 1 hour / 24 / hours / 1 week / whatever, and the winner announced in guild.