{{Template:GUI_Object|empty|none|none}}

Has no functionality; used as a container to group child objects. 

Can be used as a coordinate-system for instance, making the children relative in position. 

Empty is also the default type, which means it's possible to use an object tag devoid of properties:
{{{
  <object> 
          ...
  </object> 
}}}

This makes for a great generic container, for instance to group [wiki:GUI_-_Radio-button Radio-buttons] together. 

Notice if you give an ''empty'' control a size, it will still not block world interaction, i.e. the ''empty'' control is inherently [wiki:GUI_-_Properties#ghost ghost]. If you need a "glass layer" (a "hollow blocker" or invisible object that stops objects under it from being clicked), it's better to use an [wiki:GUI_-_Image Image] without a sprite.