About Purging Unreferenced Layers, Blocks, and Style Definitions

You can clean up your drawing by removing unused items in your drawing such as unreferenced layers, blocks, and style definitions.

The term, purge, is used to describe removing a definition rather than erasing an object. For example, erasing all objects that use a dashed linetype still leaves the linetype definition in the drawing. Similarly, erasing all block references to a fixture still leaves the block definition of that fixture block in the drawing.

A drawing that has the minimum number of unreferenced definitions open, save, use less memory, and perform faster. In addition, purging a drawing provides the following specific benefits:

• Removing unreferenced block definitions can reduce the size of a drawing file substantially.
• Removing unreferenced layers reduces the clutter in the Layer Properties Manager.
• Removing unreferenced style definitions such as text styles and dimension styles also reduces clutter in their dialog boxes and palettes.

You might want to consider exceptions to purging to maintain standardized definitions for future work.

Determine Why an Item Cannot be Purged

In some cases, it might seem that you should be able to purge an item, but you can't determine exactly why the Purge dialog box doesn't allow it. Here's a list of the most common reasons why an item can't be purged:

• Permanent definitions, such as layer 0 and all definitions named Standard
• Styles or definitions set to Current, such as the current layer
• Referenced by another style or definition, such as a text style used by a dimension style
• Used by or nested within a block or an anonymous block, such as a linetype used in a block definition or a block within another block
• Located on a frozen layer and not visible, or on a locked layer
• Referenced by an attached xref
• Referenced in paper space on a different layout tab

The Purge dialog box provides you with all the details about an item and why you cannot purge it from your drawing. Specifically, you can click the Find Non-Purgeable Items and examine the Details section to find the key information you need. You can use the Select Objects button to navigate to the non-purgeable block object and take appropriate action to make it purgeable.

The Purge dialog box also provides you with a thumbnail preview of the item selected in the tree view pane for a visual representation of the item.