Question about schematic view

[Sergio Mucino]

Very quick question. What does it mean when a node has a border around it? I've noticed even one of the illustrations in the manual depicts this... (http://download.autodesk.com/global/docs/softimage2013/en_us/userguide/index.html?url="">)... 3rd illustration from top to bottom... but there is no explanation on what that actually means. Anyone familiar with the meaning of this appearance? Thanks! --