There are multiple locations throughout BuildTools where you'll be able to add tags. Let's use project info and tasks as our examples.
Adding Tags
Let's add a new tag to a project. Start by going to Project Settings--->Project Information--->Description
Type the new tag name and hit ENTER on your keyboard to save it as a tag.
Searching Tags
Use the project drop-down search to now search by the new tag name.
This also works when searching tags in other modules such as in Tasks.
It found my task containing the Meetings tag.
If you have any questions or need help with creating tags please reach out to Support.