Every OBO ontology contains a set of categories. Terms in the ontology can be assigned to one of the categories in that set (see An Introduction to OBO Ontologies, and Text Editing for more information on how to assign entities to categories).
The built-in Subset Manager allows users to manage the set of available categories. To access the Subset Manager, choose "Subset Manager" from the menu under [Metadata].
Any changes made in the Subset Manager are not saved until the "Save Changes" button is clicked. If changes are made and the window is closed, the changes will not be saved. To revert to the last committed version of the subset set, click the "Revert" button.
To edit an existing subset, click the subset to edit in the list on the left. The subset editor panel will appear:
Categories have two attributes: a short identifying name and a longer descriptive name. To change the subset name, click the subset name in the text field and type a new name. To change the descriptive name, click the subset description in the text field and type a new description.
To delete an existing subset, click the subset to delete in the list on the left. Click the Del button to remove the subset.
Note that a subset that is assigned to a term cannot be deleted. If a subset is deleted that is still in use, a warning will appear when the "Save Changes" button is pressed. If a subset must be deleted, first search the ontology to make sure that the subset is not in use.
To add a new subset, click the "Add" button. A new subset will be created with the default name "NEWSUBSET" and the default description "<new term subset>". Edit the name and description as described above.