List the set of unique values for a property - Semantic MediaWiki Community Wiki
smw.referata.com/wiki/List_the_set_of_unique_values_for_a_property
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
One feature missing from SMW is the ability to easily list the set of unique values that have been assigned to a given property. To achieve this goal, we need to use the ArrayExtension.