This is a pretty vague announcement. What counts as "misinformation" or a "false claim" and who makes that decision? Will YouTube be contacting primary sources

This is a pretty vague announcement. What counts as "misinformation" or a "false claim" and who makes that decision? Will YouTube be contacting primary sources to verify all claims made in videos? Will they be relying on some designated "fact checkers"? Or maybe they're trying to tell us that ALL claims of voter fraud will automatically be deemed false without any form of review (this was the approach Twitter took with their labeling)?