formation 
(including formats) approaches obsolescence or is no longer viable. For most repositories, 
the concern will be with the Representation Information used to preserve information, which 
may include information on how to deal with a file format or software that can be used to 
render or process it. Sometimes the format needs to change because the repository can no 
longer deal with it. Sometimes the format is retained and the information about what 
software is needed to process it needs to change.