Some older spellcheckers had co-operation in their wordlists but not cooperation, and offered Cupertino as the first correction. Dozens of Cupertinos turned up in documents from the UN, EU and NATO, and translators gave the error its name. The term now covers any wrong word a spellchecker substitutes.
Questions people ask
Why do spellcheckers say Cupertino?
Older ones lacked the unhyphenated word cooperation and suggested Cupertino instead.