Civil 3D Reference Label Style and Component Creation
Jeff is kind enough to cover how to make and even adjust the Reference attachment in the AutoCAD Properties box.
Since the Framework for Civil 3D Style libraries includes lots of Reference Label Styles I do get questions about the ??? marks.
I love Alignment Group Label Styles often as QAQC objects to check surface elevation from various surfaces in roadways and site designs.
The InstantOn Styles Preview video covers just a few.