Task 19 was originally conceived to update, from the IUCN Red List API, the 13,000 or so articles that use {{cite IUCN}} where |url= holds an old-form IUCN url. These articles are listed in Category:cite IUCN maint (1,149).
There are several old-form urls (not all of these work):
Old-form urls are considered 'old-form' because (when they work) they always point to the current assessment.
Most of these old-form urls are used in {{cite IUCN}} templates that are found in the |status_ref= parameter of {{speciesbox}} and {{taxobox}} templates (collectively hereafter 'taxobox') to support the values in the taxobox |status= and |status_system= parameters. Because values for |status= (IUCN uses the term 'category') and for |status_system= can be extracted or derived from the results of an additional IUCN API call, task 19 was expanded to support updating these taxobox parameters.