An instrument block is a drawing b lock you associate with instrument tags. Before you can assign blocks to instruments, you must first create an instrument block type. Classification of drawing blocks according to block type is useful for filtering the blocks. It is recommended that each block type contain drawing blocks that serve the same general function. This way, it is easy to find a particular drawing block when you want to use it.
You create instrument block type and define instrument blocks in the Drawing Block Types folder of the Domain Explorer. Blocks that you add in the Drawing Block Types folder become available for association with instruments.