Sometimes i find blocks from other users in my company which i think are AutoCAD named blocks such as A$C3A7225EA. I have always been told that this is a bad thing but i am unsure why they get created & how. Sometimes we copy clip & paste things from drawing to drawing so i have a feeling this is how they get created. Am i right about this? Is this really a bad thing to have these blocks & if so, how can i keep this from happening?