英语翻译(Date changes subject to penalty plus any fare diff)请翻译下括号中的句子,plus any fare diff(difference)另补价差 全句如何理解?

问题描述:

英语翻译
(Date changes subject to penalty plus any fare diff)请翻译下括号中的句子,plus any fare diff(difference)另补价差 全句如何理解?

改日期有罚金,加上补差价 (机票等级,比如 K, J, Q那些)

Not refundable after purchase购买后无退还
Date changes subject to penalty plus any fare diff变更日期除了要付处罚金外还要补差价