4-page information security policy template on archiving important information.
 
Valuable information that must be retained long-term (for years or decades) must be properly archived to minimize the associated information risks e.g. damage, degradation, theft, loss and inappropriate access.  The policy elaborates on what it means to be 'properly archived'. 
 
Hint: there's rather more to it than stashing media in a dark corner.
 
Supplied as an MS Word document, readily customised for your organisation's specific situation.