"If you don't already have an ACADDOC.LSP file, open Notepad and input these lines:
(setvar "LAYEREVAL" 0)
(setvar "LAYERNOTIFY" 0)
"Put this ACADDOC.LSP file into a folder, which is listed in your Support File Search Path (Options>Files). That way each time a drawing is opened, the notifications will be turned off."
Notes from Cadalyst Tip Patrol: This tip touches on several different topics: Reconcile Layers and the ACADDOC.LSP file. The RECONCILE LAYER option lets you know when a new layer has been added to a file you are referencing. If you have multiple people working with the same base file, it can be very useful. It will tell you when a user creates a new layer in the file you are referencing so you can make appropriate adjustments to your layer settings. You may want to show the info they added, or you might not want to see their data. This will help you manage your files. It can be annoying though, especially if you are the one that added the new layers. The ACADDOC.LSP file will load settings every time you open a file. Adding the given code to that file will turn off the notification for the unreconciled layers. You can add any settings for any available variable to that file. This is a way to make sure your workstation runs AutoCAD the way you want it to.