So I will try to best describe it as best as I can, I am not a Japanese speaker, but I will try my best:
SCP-444-JP is a phrase that we do not know, it is most likely that the poem is part of the cognitohazard, that when someone says the phrase out loud, it will put them under a illusional world where the ground and sky are red, any interaction with their real body will have no effect in the illusional world.
After a few minutes, they will turn into a bird and feel a compulsion to fly, after flying for a few minutes, they will notice a giant red bird following them, at which point they will noticeably panic in reality.
The bird will begin to prey on them, causing massive panic and pain in reality, at which point the real body will start to attack nearby people(whether it's specifically attacking, or just thrashing I'm unsure), they will then be put into a loop with only pieces of their memory each loop. They will then somehow figure out to escape they need to write the phrase out, after which they will return to reality and will be amnestsied.
The phrase was found in a GoI called the Japan Organism Improvement and Creation Laboratory, where a agent read the phrase, he was detained and given amnestics, and the phrase was deemed a SCP. 5 months later, the same agent shot killing 4 and injuring 2, after interrogation, where he showed sever intelligence regression and ocd, it was figured out that the removed memories have reappeared, causing the incident.
In a different page, a unnamed person(most likely a doctor) states that all people under the effext of SCP 444, have seen a body killed by affected, or media containing the affected are to be set as SCP 444-JP-1(imping they now are carrier of the cognitohazard), which are contained not to be accessed by staff under authorization level 5.
They writes that the classification does not matter(it should be noted, Keter is scribbled in hand writing multiple times), saying that it's obvious what needs to be done, they will put into motion Operation Book Burn, which involves all information relating to SCP-444-JP to be erased, and all staff be amnestised, leaving only him to know about it.
They go on about the SCP, saying that if we are reading the article, it was already to late, stating "that thing is the "Bird of Preception"", likely implying the red bird, and how it has likely spread and manifested due to the article, but can at least see what it looked like while it was young, and for us to not fail like they have.