1. A method for specifying and enforcing transaction amount limits comprising: defining, by one or more computing devices, a transaction amount limit for a transaction; specifying, by the one or more computing devices, conditions under which the transaction amount limit is applicable to the transaction, comprising a unit of the transaction and an entitlement group; identifying, by the one or more computing devices, membership of a user in the entitlement group, responsive to a request from the user to perform a the transaction; identifying, by the one or more computing devices, the transaction amount limit associated with the entitlement group and the unit of the transaction, wherein the entitlement group has a negative role-based permission inheritance from a parent entitlement group such that the transaction amount limit is within boundaries of a parent transaction amount limit associated with the parent entitlement group wherein the transaction amount limit is configured to specify a rule selected from one of: (a) wherein the transaction amount limit is a first limit applicable to the transaction only if the unit of the transaction is equivalent to a unit of the transaction amount limit without a conversion, and further wherein the transaction amount limit is within boundaries of the parent transaction amount limit specified in the same unit of the transaction amount limit, or (b) wherein the transaction amount limit is a second limit applicable to the transaction regardless of the unit of the transaction, and further wherein the transaction amount limit is within boundaries of the parent transaction amount limit specified as applicable regardless of the unit of the transaction, wherein the first limit and the second limit are set independently of each other; and processing, by the one or more computing devices, the transaction if the transaction satisfies the transaction amount limit based on comparison of the converted amount limit and/or converted amount of the transaction.