(hex:99) is a glitch item in Pokémon Yellow. It is an unterminated name glitch item.
It appears to have the same effect as SoulBadge (hex:19), and using it will return Professor Oak's message that it isn't the time to use it.
Glitch City Laboratories closed on 1 September 2020 (announcement). This is an archived copy of an article from Glitch City Laboratories wiki.
A live version of this article is available at the Glitch City Wiki here.
You can join Glitch City Research Institute to ask questions or discuss current developments.
You may also download the archive of the wiki in .tar.gz or .xml.gz formats.