这事没有什么硬性的规定。

There are no hard and fast rules about this.

《牛津词典》

从全球来看，掌握一门以上的语言在许多领域被视为一种优势，甚至是一种硬性的要求。

Globally, knowing more than one language is viewed as an asset and even a necessity in many areas.

youdao

这不是一个硬性的规则。

This isn't a hard rule.

youdao

It would be utterly inadequate for us to account for this institutional and surreal institutional power that Milton holds over us by stating blandly that Milton is the greatest English poet.

要解释弥尔顿为什么能对我们施加,这样硬性的甚至荒诞的控制,仅仅说弥尔顿是最伟大的英国诗人是远远不足的。

耶鲁公开课 - 弥尔顿课程节选

I would say, part of what we look at are hard quantitative factors, but probably more important than the numbers are the soft qualitative attributes.

我想,我们看重的,是一些硬性的量化因素,这可能比那些抽象的特质属性,更为重要

耶鲁公开课 - 金融市场课程节选

Originally, they were very rigid about this.

起初，规定是硬性严格的。

耶鲁公开课 - 金融市场课程节选