Wikipedia对“blackacre”作出了如下解释：

“Blackacre, Whiteacre, Greenacre, Brownacre, and variations are the placeholder names used for fictitious estates in land.

The names are used by professors of law in common law jurisdictions, particularly in the area of real property and occasionally in contracts, to discuss the rights of various parties to a piece of land. A typical law school or bar exam question on real property might say:

Adam, owner of a fee simple in Blackacre, conveyed the property "to Bill for life, remainder to Charles, provided that if any person should consume alcohol on the property before the first born son of Charles turns twenty-one, then the property shall go to Dwight in fee simple." Assume that neither Bill, Charles, nor Dwight is an heir of Adam, and that Adam's only heir is his son, Edward. Discuss the ownership interests in Blackacre of Adam, Bill, Charles, Dwight and Edward.

Where more than one estate is needed to demonstrate a point – perhaps relating to a dispute over boundaries, easements or riparian rights – a second estate will usually be called Whiteacre, a third, Greenacre, and a fourth, Brownacre.”

从上述内容可以看出，“Blackacre”“Whiteacre”“Greenacre”“Brownacre”用于普通法适用区域，用来指代虚拟的地产，如果涉及一个以上地产，第一个称为“Blackacre”，第二个称为“Whiteacre”，第三个称为“Greenacre”，第四个称为“Brownacre”，相当于中文中的“甲地”“乙地”“丙地”“丁地”，以便通过举例讲授或解释物权法相关概念时对各个地产进行区分，便于描述。

例句：

原文：

Julian is the life tenant of a settlement comprising Blackacre, Whiteacre and Greenacre plus various other investments.

After Julian’s death the trustees carry out the following actions:

They grant a depreciatory lease of Blackacre. Had this been in place at the death the value would have been reduced to £36,000.

They demolish the porch at Whiteacre. Without the porch the value at the death would have been reduced to £49,000.

They exchange Greenacre for listed securities at a time when its value is £22,000.

They purchase Blueacre for £17,200.

译文：

Julian是由甲地、乙地和丙地构成的地产加上其他各种投资的终身保有人。

Julian去世后，受托人采取了下列行动：

受托人对甲地进行了折旧出租。如果Julian去世时就对甲地进行了折旧出租，那么甲地的价值将减少至36,000英镑。

受托人拆除了乙地的门廊。如果Julian去世时乙地就拆除了门廊，那么乙地的价值将减少至49,000英镑。

受托人在丙地价值为22,000英镑时用丙地换取了上市证券。

受托人以17,200英镑购买了丁地。

来源：

Wikipedia；

www.gov.uk