When you add an object that supports captions, LiveCycle Designer ES assigns a default name for the caption. The default name is the name of the object. For example, if you add a list box object to the form design, the default caption is List Box.
When creating the form design, you can see the caption for the object in two places: on the form design (above the object (the default position)) or in the Field tab of the Object palette.
You can edit the caption text by using the Field tab of the Object palette or by editing the caption text directly on the page. If the text wraps as you type, increasing the size of the object will display the text properly. If the object displays a white cross in a red box Livecycle captions.61.2.1 About captions, the object either needs to be resized or have the caption reserve adjusted. A reserve of 0 sets the caption area to auto-fit so that it adjusts to fit the entire caption. The caption is protected and users cannot be modified it when filling the form.
If you need to rearrange field objects, but do not want to risk modifying their captions, you can use the Lock Text command. Using this command lets you to move the field objects around easily but makes the caption not as easy to modify.
See also 

About captions