With Kanboard, you can associate one or many tags to a task. You can define tags globally for all projects or only for a specific project.

Tags on the board

From the task form, you can enter the desired tags:

Tags form

The auto-completion form will show up to suggest available tags.

You can also create tags directly from the task form. By default, when you create tags from a task form they are associated to the current project:

Project Tags

All tags can be managed in the project settings.

To define tags globally for all projects, go to the application settings:

Global Tags

To search tasks based on tags, just use the attribute "tag":

Search Tags