The English Sustainable Development Goal icons in inst/extdata/sdg-icons are
unmodified assets published by the United Nations. They were obtained from:

https://www.un.org/en/content/files/E%20SDG%20Icons%20PRINT.zip

The icons and Sustainable Development Goal branding remain the property of the
United Nations. Their inclusion does not imply United Nations endorsement of
this package. Users remain responsible for following the United Nations
Sustainable Development Goals communications materials guidelines.