https://www.fai.org/sites/default/files/civl/documents/sporting_code_s7-common_2018.pdf

2.5.5 Minimum Representation

For World Championships a minimum of 4 countries with a total of 8 competitors
available to fly during the Championship is required for the title of Champion
to be awarded; for Continental Championships, a minimum of
3 countries with a total of 8 competitors is required.

This exception to the standard rule of four countries will apply to the
2020 Pan-American Championships in Big Spring, Texas.