Error 1: The sentence beginning with "They take place in the Alola Region..." does not end with a period.
Error 2: The word "section" in the sentence beginning with "Details about this game are..." is misspelled.
Link: http://www.serebii.net/ultrasunultramoon/
Error 1: In the description at the top of the page, "Ultra Sun" has a space in the middle, whereas "UltraMoon" does not.
Error 2: Under the heading for I Choose You Cap Pikachu, its US Name is listed as unknown even though the twentieth movie has recently had its overseas title confirmed.
Error 3: Under the heading for I Choose You Cap Pikachu, its weight is listed as unknown even though its height has been assumed to be equal to the existing Pikachu in a Cap variants.
Error 4: Under the heading for Lycanroc Dusk Form, the move Accelerock is misspelled as "Accelrock" on the Known Moves list.
Link: http://www.serebii.net/ultrasunultramoon/forms.shtml
Error: On the front page of the Serebii Forums, the "Pokédex" link at the top of the page links to the Black & White Pokédex instead of the Sun & Moon Pokédex.
Link: http://www.serebiiforums.com/
Error 1: In the sidebar on the main website, the Generation III Pokédex is labeled as the "R/S/C/FR/LG/E Pokédex", with an extra "C" in the name (unless the "C" is for Colosseum in which case the name is missing a reference to Pokémon XD).
Error 2: In the sidebar on the main website, the Sinnoh games' abbreviation for the Pokédex is "DPt", for the Attackdex is "DPPt", and for the Spin-Off Pokédex is "DP".
Link: http://www.serebii.net/index2.shtml