The tagging notes existed since the wiki's creation. At the time, Futanari and Newhalf were very separated from each others and treated as completely different things, so it was necessary to determine if a dickgirl in a post was either a Futanari or a Newhalf.
The first and main detail was if the character lacked pussy. However not every futanari or newhalf art will show the entire crotch region to determine that. So when in doubt, it gets tagged as futanari just for precaution.
I said before that Newhalf isn't a canon tag, but it turns out it kinda works like one actually (only NSFW posts showing either bulge or penis) with outside information such as knowing the characters is a Newhalf, artist's tags and commentary. Isn't it basically how we tag Otoko no ko characters? We need outside information allied with what we see in the picture when tagging Otoko no ko, if not, most of them would be tagged as 1girl.
Now, talking about concept and lore, I said before in other forum topics that "Futanari are girls who magically grew a dick, and Newhalf are boys who grew boobs through implants", emphatizing the fantastical nature of Futanari, while on the other hand, Newhalf are directly based on real life.
Let's look at post #2602438. We know for a fact this artist specifically never draw Futanari, only Newhalfs. The newhalf tag was very likely one of the tags in the pixiv post (it's now a bad link). The characters have large breasts and female clothing; but facial features and body structure are still reminiscent of masculine. Not every artist draw Newhalfs with this detail, so it is technically another way to visually identify a Newhalf in a post. For all these reasons, I believe these tagging notes should still be valid as a way to identify Futanari posts where there are Newhalfs being depicted.
