The conjunction 至于
The conjunction 至于 
is used when the speaker wants to comment on a topic related to a previously discussed one.
is used when the speaker wants to comment on a topic related to a previously discussed one. Pay attention
It is used in written language.
Examples
至于费用问题，还要再讨论
The cost should be discussed
zhìyú fèiyòng wèntí, hái xūyào zài tǎolùn
学校决定下个月举行运动会，至于具体时间，请待学校通知
The school has decided to hold a sports day next month. The exact date will be announced later
xuéxiào juédìng xià ge yuè jǔxíng yùndònghuì, zhìyú jùtǐ shíjiān, qǐng dài xuéxiào tōngzhī
超市将于节日期间举行优惠活动，至于详细情况，可上网查查
There will be special promotions in our supermarket during the holidays. You can find more information on our website
chāoshì jiāng yú jiérì qíjiān jǔxíng yōuhuì huódòng, zhìyú xiángxì qíngkuàng, kě shàngwǎng cháchá