Simplify the following text for a Grade 6 native English-speaking person.
Original: MissingNo . , also known as MissingNO , is the name of a glitch PokÃ mon that is short for `` Missing Number '' .
Simplified: MissingNo . , or MissingNO , is a PokÃ mon species found in the video games PokÃ mon Red and Blue . Standing for `` Missing Number '' , MissingNo .