When you create a definition of the User Defined IDF Table definition type, an empty IDF Table is created with a single Duration Column and no Return Period rows. You can add or remove Durations and Return Periods using the buttons above the table.

When editing a definition of the User Defined IDF Table definition type, the tabbed area of the dialog contains the following controls:

Storm Data Input Tab

Add/Remove Return Periods: Opens a submenu containing the following commands:

Delete Return Period—Use the Delete command to remove the currently highlighted column from the table.

Add/Remove Durations: Opens a submenu containing the following commands:

Delete Duration—Use the Delete command to remove the currently highlighted row from the table.

Notes Tab

This tab contains a text field that allows you to enter descriptive notes that will be associated with the currently highlighted storm data definition.

Library Tab

This tab displays information about the storm data definition that is currently highlighted in the list pane. If the storm data definition is derived from an engineering library, the synchronization details can be found here. If the storm data definition was created manually for this model, the synchronization details will display the message Orphan (local), indicating that the storm data definition was not derived from a library entry.