quality:correction, information:classification
Equitable lien

In common-law countries, equitable liens give rise to unique and complex issues. An equitable lien is a nonpossessory security right conferred by operation of law, which is similar in effect to an equitable charge. It differs from a charge in that it is nonconsensual. It is conferred only in very limited circumstances, the most common (and least ambiguous) concerning the sale of land; an unpaid vendor has an equitable lien over the land for the purchase price, notwithstanding that the purchaser has gone into occupation of the property. It is seen as a counterweight to the equitable rule, which confers a beneficial interest in the land on the purchaser once contracts are exchanged for purchase.