Begin modifying a task by right clicking it and then clicking Modify Task.
If you’re interested in the other methods available for accomplishing this, please refer to Modifying Task Details.
In the Modify Task dialog navigate to the Custom Fields tab and then click on Add New Custom Field…
Using the Create Custom Field field dialog you will be able to create a custom field with a name, default value, and notes:
Any Custom Field which is created will then appear under the Custom Fields tab while modifying a task:
Any value entered into a custom field will be saved for accessing in the future. If you have three types of work for example, you will be able to pick one from the “Type of Work” drop-down the next time you need to fill out such a custom field.
To modify or delete existing custom fields, please refer to Modifying Custom Fields.