Remove Block Definitions; Create And Modify Blocks; Define Blocks - Autodesk 057B1-41A111-1001 - AutoCAD LT 2010 User Manual

Block reference with constraint (gray) and constraint parameter (blue, with grip)
You can select a block reference and list its editable parameters with
-PARAMETERS. When you change the value of the parameter, the block
reference is updated accordingly.

Remove Block Definitions

To reduce the size of a drawing, you can remove unused block definitions.
You can remove a block reference from your drawing by erasing it; however,
the block definition remains in the drawing's block definition table.
To remove unused block definitions and decrease the drawing size, use PURGE
at any time in your drawing session.
All references to a block must be erased before you can purge the block
definition.
See also:
Overview of Blocks

Create and Modify Blocks

A block definition is a set of objects that are grouped together as one named
object with a base point and unique properties.

Define Blocks

You create blocks by associating objects and giving them a name.
278 | Chapter 7 Define and Reference Blocks
(page 269)