Autodesk AUTOCAD 2006 Command Reference Manual page 571

The last block you insert during the current editing session becomes the default
block for subsequent uses of INSERT. The position of the inserted block depends
on the orientation of the UCS.
Name
Specifies the name of a block to insert, or the name of a file to insert as a block.
Angle
Sets a rotation angle for the inserted block.
Browse
Opens the Select Drawing File dialog box (a standard file selection dialog
box) where you can select a block or drawing file to insert.
Factor
Displays the unit scale factor, which is calculated based on the INSUNITS
value of the block and the drawing units.
Path
Specifies the path to the block.
Preview
Displays a preview of the specified block to insert. A lightning bolt icon in
the lower-right corner of the preview indicates that the block is dynamic.
Specify On-Screen
Specifies the insertion point of the block using the pointing device.
Insert Dialog Box | 547