It's a Reddit link [please don't throw things at me] so I've broken the link intentionally here. Remove the underscore in "red_dit", copy and paste into new window and you're good to go.
CAUTION: there is all likelihood that when combing open directories....... you WILL come across some messed up shit. These are usually directories that some folk assume no one will find. You were warned.
https://governmentattic.org/8docs/UntanglingTheWeb-NSA_2007.pdf
vs
Those reddit data. New tricks or already described tricks ?