What does CHECCA stand for?

Chen Caerulescens Caerulescens - Scientific name - Common English name: Lesser Snow Goose Intermediate-Morph - American Ornithologists Union six-character bird identification (IBP)

Chen Caerulescens Caerulescens - Scientific name - American Ornithologists Union six-character bird identification - Common English name: Lesser Snow Goose Blue-Morph (IBP)

Chen Caerulescens Caerulescens - Scientific name - American Ornithologists Union six-character bird identification - Common English name: Lesser Snow Goose White-Morph (IBP)