Anonymous Blocks in AutoCAD
From Draftsperson.netWritten By Allan using AutoCAD 2004
"AutoCAD uses anonymous blocks for supporting hatch patterns and dimensions. These types of blocks are also created using AutoLISP or similar means, but cannot be intentionally created in the drawing editor. Also, anonymous blocks cannot be modified using AutoCAD editing commands." - www.autodesk.com.au
What are the Types*U### = anonymous blocks
*E### = anonymous non-uniformly scaled blocks
*X### = anonymous hatches
*D### = anonymous dimensions
*A### = anonymous groups