You can use the taxonomy condition so that when a node is viewed with either a specific taxonomy term or a term from a particular vocabulary a context is activated.
If you wish to use the a vocabulary or its terms in this way you must first activate context on that taxonomy, to do so you will need to:
- Go to the taxonomy settings page, Admin > Content Management > Taxonomy.
- Find the vocabulary that you want to use and click 'edit vocabulary' in the 'operations' column.
- Find the 'Include as context condition' check box and ensure it is ticked
- Submit the form and you should now be able to use the taxonomy as a condition in your context definition.