The term "ratable" generally means something that can be assessed, evaluated, or rated according to some established criteria or standard.
In a legal or tax context, ratable can refer to property or assets that are subject to assessment for the purposes of determining their value and the amount of taxes owed on them. For example, real estate or personal property may be considered ratable by a local government for property tax purposes.
In a business context, ratable revenue refers to revenue that is recognized and recorded over time as opposed to being recognized all at once. This can be important for companies that have long-term contracts or subscription-based models, as they may need to spread the revenue they earn over the life of the contract or subscription.
Overall, the term "ratable" suggests something that can be evaluated or assessed according to some established criteria, and may be used in a variety of different contexts.