Choose Edit Fields of the context menu of the selected field.
Type
Shows the type of the selected field.
Select
Lists the available fields for the field type selected in the Type list. To insert a field, click the field, and then click Insert.
Format
If a field is displaying a date, time or number, then Format is used to customize the appearance of the date, time, or number. Common formats are shown in the Format window, or click "Additional formats" to define a custom format.
Invisible
Hides the field contents in the document. The field is inserted as a thin gray mark in the document. This option is only available for the "Set Variable" and "User Field" field types.
Value
Enter the contents that you want to add to a user-defined field.
Apply
Adds the user-defined field to the Select list.
Apply
Arrow buttons
Use the arrow buttons to go to next or previous field of same type in the document.
Edit
When visible, opens a dialog to edit the contents of the field. The dialog depends on the type of the field.