Since I cannot guess which one you intend, I will provide the most likely and useful answer: written as if “Index of True Legend” were a proposed methodological tool in comparative folkloristics and digital legend studies.
(Mason Locke Weems, 1806): Young Washington chopped down a cherry tree and confessed, “I cannot tell a lie.” index of true legend
Measures how consistently core claims survive transmission without motivated alteration. Since I cannot guess which one you intend,