known-limit的中文是什么意思呢

可知的限度。如果前面加上has no则是无限的意思

LZ好，是 warranty 吧？
保证,担保书,担保

以下供参考：

warranty
n.
pl. war.ran.ties;
【复数】 war.ran.ties;
Official authorization, sanction, or warrant.
授权，批准官方授权、批准或认可
Justification or valid grounds for an act or a course of action.
依据为某一行为或某项事业提供支持证明其有效之事（物、言辞等）
Law
【法律】
An assurance by the seller of property that the goods or property are as represented or will be as promised.
保证货物卖主所作的货物同样品无差别或与许诺相同的保证
The insured's guarantee that the facts are as stated in reference to an insurance risk or that specified conditions will be fulfilled to keep the contract effective.
合同担保关于被保的风险如实或为保证合同有效而设立的条件将全部执行的保证
A covenant by which the seller of land binds himself or herself and his or her heirs to defend the security of the estate conveyed.
地产契约土地卖主作出的他（她）本人及他（她）的继承人受法律约束以保护转让地产的安全契约
A judicial writ; a warrant.
法庭书面状；委任状
A guarantee given to the purcha