Defining the data element Use the Definition of the Selected Data Element pane to modify existing or define new data elements. Click the element name in the Defined Data Elements pane. The selected element’s definition displays in the Definition of Element pane. For Type click the arrow to open a list of types. For Length click the arrow buttons to select the maximum number of characters that one instance of the data element can occupy in a message. Select Unlimited for an unlimited field length. For Minimum Length click the arrow buttons to select the minimum length of the added or edited field.