By default, user-defined fields allow you to enter up to 100 characters of descriptive information. These descriptive fields can then be used to group reporting, based off of cost center, location, etc (note that the UDF selection names are set up on the Text tab of System Options). You may choose to require entries to be selected from a list. To do this, check the box for the user-defined field on the left of the UDF Choices tab, then select the field on the right side of the tab and enter a list of valid choices (you can delete old or incorrect entries by selecting the value and hitting "delete" on your keyboard).
You may also create lists for the asset class and financial group fields, which may store up to 50 characters each. These two fields are set up by default, and cannot be changed or renamed.
You may populate the list with all values in the currently open database for that field by holding down the Shift key while clicking on the checkbox or name of that field on this tab.