"Tagging" your servers and sites can make them easier to manage, especially if you have many servers / sites. Servers can be tagged via the server dashboard's Settings tab's Server Settings section, while sites can be tagged via the site Settings tab.
You may delete tags and their associations from Forge's tags dashboard.
Once servers and sites have been tagged, you may filter by those tags via Forge's search bar located in the top navigation panel of the Forge dashboard. Alternatively, you may filter by your tags from the Forge active server list.