Learn Farsi: باید حداقل لباس را ببرید تا جریمه نشوید. - You must take a minimum amount of clothes so you don't get fined.

حداقل (had-e-aqal) means 'minimum' or 'at least'. Just like the expressions of maximum capacity you are learning, it acts as a limit modifier. Here, it sits directly before the noun as حداقل لباس (a minimum amount of clothes). Its exact opposite, 'maximum', is حداکثر (had-e-aksar).

Why do we use the direct object marker را after حداقل لباس? Isn't 'a minimum amount' indefinite?

In English, 'a minimum' sounds indefinite. However, in Farsi, the speaker is referring to a specific, understood limit (for example, a strict airline baggage limit). Because it refers to that specific minimum threshold of clothes rather than just any random amount, it takes the definite object marker را.

There are two subjunctive verbs in this sentence (ببرید and نشوید). What is triggering each of them?

You likely remember that باید (must) always requires the subjunctive, which gives us ببرید (from بردن, to take/carry). The second subjunctive, نشوید, is triggered by the conjunction تا (so that / in order to). When تا introduces a goal or purpose, the verb in that clause must also be in the subjunctive.

I often mix up the different Farsi verbs for 'to take'. Why is بردن used here instead of گرفتن?

بردن (bordan) means 'to take' in the sense of transporting, bringing, or carrying something from one place to another (like packing clothes for a trip). (gereftan) means 'to take' in the physical sense of grasping, catching, or acquiring something.