Michal Koc sent us a tip on setting up and using Layer Filters.  He said that in his company they work on AutoCAD 2006.  Usually they use a lot of xrefs in every drawing, so it's very annoying in Layer Manager/Layer List to see thousand of xref layers.  The easiest way to hide all xref layers in Layer List is to make a Layer Filter, e.g.,

"NoXREF"

This shows all layers without the | sign, which is used in every xref layer.  To do this, just open Layer Properties Manager, then use ALT+P (or the icon in upper left corner of the window) to create New Property Filter.  In the Layer Filter Properties window in the Filter Name box, just type the filter name "NoXREF" and  ~*|*in Name column of Filter definition box.

(To create the "|" symbol just press and hold the ALT key and then press 1,2,4 from the numeric keypad)

To use the NoXREF filter, just one click on NoXREF from left column of Layer Properties Manager window.


NOTES FROM CADALYST TIP PATROL:  Layer filters are very valuable, so this is a good tip.  Create a new filter as described above, give it a name, and then in the Filter Definition area, describe what you are filtering in the name field.  The Tilde (~) tells the filter to remove the following items from the list.  If there is no tilde, then only layers with the definition will be shown.  The asterisk (*) is a wild card.  The | key can be inserted by shift + .  (The | key should be there on a standard QWERTY U.S. English Keyboard.)
Tested in AutoCAD 2009