Hello CHulse.
The data was defined in tables, which were then assigned to the elements (blocks).
I explain what is inside the document that I uploaded, on the left side there is a rectangle with the legend of the elements that appear in the drawing.
Inside that rectangle there are two smaller rectangles, the first on the top are the elements of the "POLES" type and the second on the bottom are the elements of the "PROPERTY" type.
If you select an element and look at the properties of the selected element, you will find below a property called "OD", if I select a "POLE", it will say that property "OD:POLES", if I select a "PROPERTY", it will say "OD:PROPERTY", those are table fields that were created in AutoCAD Map 3D from the "MAP CONFIGURATION" toolbar, in the option called "DEFINE OBJECT DATA", when you click on that option , a window will appear where it shows several tables, the tables that have the fields of those elements are the "POSLES" table and the "PROPERTY" table.
I hope I have helped you with this explanation. Any questions, do not hesitate to contact me.
Thank you so much.
Greetings.