(De-)Select Layer
Toolbar / Icon:
 
   
 
   
Menu: Select > (De-)Select Layer
Shortcut: T, L
Commands: selectlayer | tl
Description:
Selects or deselects all entities on the same layer as a chosen entity.
Procedure:
  
- Choose the 
selection mode in the options tool
bar.
- Use the mouse to pick one entity on the layer you want to (de-)select. 
All entities that are on the same layer as the entity you have picked 
match and are selected or deselected depending on the selection mode.