Exactly, some rules are meant to be broken. If the user is believed to be in northern California and types 'San ', then "San Francisco" should probably be hig

Exactly, some rules are meant to be broken. If the user is believed to be in northern California and types 'San ', then "San Francisco" should probably be higher up the list than "San Diego" despite that not being alphabetical order. Determining whether or not the autocompletion should work like this is a matter of common sense applied by the developer, there is no hard and fast rule. In some hypothetical circumstances it may make more sense to sort by population size, rather than geographic proximity (let alone alphabetically.)