These Are still used these can include stylesheets linetyper layers blank styles and so on. This is a great way to visually check the structure of the blocks in your current drawing. IF You use data mining you can also make a list of all the blocks used in your drawing or project with quantities and other data in the list. However because there is a small group of layers that is not actually used in the drawing or template they are purgable or erasable. My old company actually had people who were involved in writing the code for AutoCad on the payroll so hopefully what Im looking for is not some intensive computer programming issue.Are these still being used These can include styles linetypes layers plot styles and so on.This is a nice way to visually check the structure of the blocks in your current drawing.Also if you use data extraction you can make a list of all blocks used in drawing or project with quantities and other data in that list.But since there are a small group of layers that are not actually used in the drawing or template they are purgable or deletable.My old company actually had people that were involved in writing the code for AutoCad on the payroll so hopefully what Im looking for isnt some intense computer programming issue.