Measuring quality (narrow focus)
Fragment of a discussion from Talk:Task force/Wikipedia Quality
The key is that the sentence has to be verified in something independent and reliable. And it can't be verifying the mere existence, or just anything.
"Tommy Smith was a World War 2 Veteran.(cited to a personal website) World War 2 was a global conflict that involved most of the world's nations, including two major alliances: the Axis and the Allies.(cited to a published history book)"
I'm digging into details here. But details are important.