Editing Module:Cite IUCN/doc (section)

===Legacy issue with old-style urls===

There is still a legacy issue with old-style IUCN urls, which are still used in many Wikipedia citations.

Some months after the change to the new-style urls, the IUCN introduced redirects for the old-style urls that link to the appropriate pages addressed by the new style url. In most cases these redirects will work. So the oldstyle url for the tiger <code><nowiki>https://www.iucnredlist.org/details/15955/0</nowiki></code> correctly links to the assessment at <code><nowiki>https://www.iucnredlist.org/species/15955/50659951</nowiki></code> (see [https://www.iucnredlist.org/details/15955/0 tiger]). 

However, not all assessments redirect. For instance, the oldstyle url for the Bengal mud eel <code><nowiki> http://www.iucnredlist.org/details/166410/0</nowiki></code> links to the home page (see [http://www.iucnredlist.org/details/166410/0 Bengal mud eel]).

This failure of some old style url to be redirected is unexpected, as the redirect function of the IUCN API does link to the correct page. A url of the form 
:<code><nowiki>https://apiv3.iucnredlist.org/api/v3/taxonredirect/166410 </nowiki></code>
: will link to the correct page, even in cases where the automatic redirect faile, e.g. the [https://apiv3.iucnredlist.org/api/v3/taxonredirect/166410 Bengal mud eel]. 

However, redirects are not available when the taxon id has been replaced and an error in JSON format is returned (e.g. for [https://apiv3.iucnredlist.org/api/v3/taxonredirect/149100 house sparrow]).