The Gaiwiio was transmitted orally in the years after Handsome Lake's death and was later set down in writing, most influentially in a version recorded from a Seneca reciter by the ethnographer Arthur C. Parker in the early twentieth century. It continues to be practiced today as the Longhouse religion, sometimes called the Code of Handsome Lake, among some, not all, Haudenosaunee communities, with recitation of the code remaining a living annual practice in longhouses that maintain the tradition.
This entry is filed on the umbrella Native American Religion record with its Seneca and Haudenosaunee origin stated specifically throughout, following the same practice this atlas already applies elsewhere on this record, for example its existing notes on Orenda as a documented Haudenosaunee concept. Handsome Lake's movement is a Seneca originated development from 1799 onward, not a survival of pre-contact Haudenosaunee religion unchanged, and not representative of other Native nations' traditions.
The Code is recited in full over a period of days at designated Longhouse gatherings each year, an oral performance tradition that has itself been maintained and passed down across generations of reciters since Parker's early twentieth century recording, making the Gaiwiio one of the more thoroughly documented cases of a Native American religious movement's transmission history.