这可能以特定的设置值(例如所有的9或‘Do Not Use’)或空白值(一个空白表示一个按键，这不同于一个null值)的形式出现。

This may be in the form of specific set values (for example, all 9's or 'Do Not Use') or blank values (where a blank represents a keystroke distinct from a null value).

youdao

他表示，再也不能给承包商发放空白支票了。

He says no longer will contractors be given "a blank check."

youdao

在加拿大，已经采用Populated的一致性强度来填补了Required和Mandatory之间的空白，其表示必须使用数据支持的元素(其不能为空)。

In Canada, a conformance strength of Populated has been adopted to fill a gap between Required and Mandatory, representing an element that must be supported with data (it cannot be empty).

youdao

- Now the bottom-- the little underscore in the bottom right hand corner represents the blank tile and just as with my thumbs I would move 4 down or maybe 2 to the right.

现在下方,右下方的下划线表示空白片,我可以用手指将4移下来,或者将2移到右边。

哈佛公开课 - 计算机科学课程节选