Except the server-side "autocomplete" method which could be used to collect suggestion strings according to entered prefix, rich:autocomplete allows to define similar method for filtering at client side. It should be defined using clientFilterFunction attribute which accepts custom filter function name. Function should accepts two parameters subString(current input value considering tokens) and value(currently iterated item value) and return boolean flag which means if the value satisfies the substring passed. The function will be called for every available suggestion in order to construct new list of suggestions.

This sample shows how to change the client filtering to "contains" instead of "startsWith"