Main conclusion: Kopyor and macapuno are two coconut mutants from Southeast Asia that are often described erroneously or interchangeably mismatched due to a lack of research, so future studies are encouraged. Coconut (Cocos nucifera L.; Arecaceae), a widely distributed plant with popular culinary applications, especially of the endosperm, has several nutritional and medicinal benefits. Two coconut mutants are widely recognized in Southeast Asia, namely kopyor and macapuno, specifically in Indonesia and Philippines, respectively. Kopyor coconut is known for its brittle solid endosperm while macapuno coconut is known for its gelatinous solid endosperm. Both mutant types have many other synonyms in other countries. Over many decades, the biology of macapuno coconut, including endosperm anatomy, histology, cytology, physiology, and genetics have been described, while kopyor coconut is still understudied. However, some literature and websites erroneously describe kopyor as macapuno coconut, or consider them interchangeably, which is an unintentional consequence of insufficient scientific research on these coconut mutants. Additionally, in Indonesia, there is another local mutant in Banten called wax coconut ("kelapa lilin") that some researchers claim as the actual Indonesian macapuno coconut due to its strong resemblance to kopyor coconut. Unfortunately, wax coconut is not only understudied, it is rarely documented. Additional evidence of their differences, in terms of morphological, biochemical and genetic characteristics, is needed. Moreover, clear documentation will also be needed for a better comparison. Understanding the differences between kopyor and macapuno coconuts will not only help to further clarify their scientific description in the literature, but will also guide locals, researchers, and industries to characterize similar mutants, if found in specific regions, for future study and bioprospecting. [ABSTRACT FROM AUTHOR]