You can edit the values and other properties of all attributes that are already attached to a block and inserted in a drawing.
You can modify attributes in block definitions with the Block Attribute Manager. For example, you can modify the following:
By default, attribute changes you make are applied to all existing block references in the current drawing.
Changing the attribute properties of existing block references does not affect the values assigned to those blocks. For example, in a block containing an attribute whose tag is Cost and value is 19.99, the 19.99 value is unaffected if you change the tag from Cost to Unit Cost.
Updating attributes with duplicate tag names can lead to unpredictable results. Use the Block Attribute Manager to find duplicate tags and change tag names.
If constant attributes or nested attributed blocks are affected by your changes, use REGEN to update the display of those blocks in the drawing area.
When you define a block, the order in which you select the attributes determines the order in which you are prompted for attribute information when you insert the block. You can use the Block Attribute Manager to change the order of prompts that request attribute values.
You can remove attributes from block definitions and from all existing block references in the current drawing. Attributes removed from existing block references do not disappear in the drawing area until you regenerate the drawing using REGEN.
You cannot remove all attributes from a block; at least one attribute must remain. If you need to remove all attributes, redefine the block.
You can update attributes in all block references in the current drawing with changes you made to the block definition. For example, you may have used the Block Attribute Manager to modify attribute properties in several block definitions in your drawing but elected not to automatically update existing block references when you made the changes. Now that you are satisfied with the attribute changes you made, you can apply those changes to all blocks in the current drawing.
Updating attribute properties in block references does not affect any values that have been assigned to those attributes.
You can select an attribute in a block reference and use the Properties palette to change its properties, or you can use the Enhanced Attribute Editor to modify all the attributes in a selected block reference.