I got the following response from a SAS representative a while back when I noticed the same problem:   The EG data grid does not currently support setting special missing values.  I will add this as a requirement to the EG data grid, since it should handle this better (and as you experienced, can too easily result in a data integrity issue).   In the meantime, if you wish to simply view a raw value, press the Esc key (rather than the Enter key or clicking elsewhere) when you wish to leave edit mode for a cell, so the value is not committed back to the source ... View more