Create datasets which don't show up in file listings

If you name a SAS dataset starting with "_to" or "_tf" then they will not
appear in the following places:

- Proc Datasets
- Proc contents
- Libname window
- SAS Explorer window

This can be a useful technique to use if you want to create a "hidden"
dataset - but beware as using Proc Datasets on one of these files can
produce errors. Read the technical support note for more information ...
http://support.sas.com/techsup/unotes/SN/004/004367.html

Sample Code
-----------
data _top ;
  set sashelp.class ;
run ;

Tested under SAS 9.1.3 & Windows XP Professional
Wood Street Consultants Ltd.            t...@woodstreet.org.uk
www.woodstreet.org.uk