User defined fields allow you to create and maintain data specific to your organization. For example, you can track additional activity data, such as delivery dates and purchase order numbers. You can also track additional resource data or project cost-related data, such as profit, variances, and revised budgets. User defined fields are global, so they can be used across all projects in your organization.
You can also create project user defined fields. Project user defined fields track information specific to projects. For example, your organization might require a custom field to track project profit. Project user defined fields are unique in that you can define a formula or statement to automatically calculate field values, and identify graphical indicators to display for a field, based on its value.