<http://schema.org/description>
"Steve Harman, a SubtextDeveloper, writes up a helpfuldescriptionof how to use the varyByCustom parameter of thePartialCachingAttribute."^^<http://www.w3.org/2001/XMLSchema#string>
<http://haacked.com/archive/2006/05/15/CustomPartialOutputCaching.aspx/>