I have drawings that have blocks that consist of nothing but attributes. Apparently, in the past, someone would just change the attribute values to null instead of erasing the block. So, in some cases, I have several blocks in a drawing that are invisible in unpurgeable. Also, I don't already know the names of said blocks. I need to write a routine to erase these. That's simple enough, but I'm stumped on how to create a selection set of blocks that contain only attributes and those attributes are all null. Can anyone help?