NEW IN R21
This setting can be used to change the Material Node’s name. If you happen to forget what function a given Node has due to its modified name, its original name will still be shown in the Info area of the Node Editor when the Node is selected.
Each Material Node can be modified due to program updates or other changes. This is why the Nodes use a type of version number internally. Using this menu, the desired version can be selected or the latest version can be used to ensure that the most current version of the Node is used.
More information about versioning can be found under the Version tag.
To get a better overview of complex materials, the top part of the Material Node can be colored individually in the Node Editor by enabling this option. Use the Node Color setting to define the desired color.