Here are a few options for the description of a WordPress post tag with the title “法定貨幣” (Fǎdìng huòbì – Fiat Currency) in Traditional Chinese, ranging from concise to more informative:

**Option 1: Concise & Direct**

* **Description:** 政府發行的、被法律認可的貨幣。

* **Translation:** Currency issued by the government and recognized by law.
* **Explanation:** This is a straightforward and accurate definition.

**Option 2: Adding Context for Readers**

* **Description:** 由政府發行，並得到法律承認的貨幣，其價值由政府的信用所支撐，而非與實體商品（如黃金）掛鈎。常見的法定貨幣包括美元、歐元等。

* **Translation:** Currency issued by the government and recognized by law, whose value is backed by the government’s credit, rather than tied to a physical commodity (like gold). Common fiat currencies include the US dollar, euro, etc.
* **Explanation:** This clarifies the backing of fiat currency and provides examples.

**Option 3: Focusing on Alternatives and Comparison**

* **Description:** 指由政府發行並被法律賦予支付效力的貨幣，而非與實物資產（例如黃金）掛鉤。相對於加密貨幣及其他另類貨幣，法定貨幣是金融體系中的主要流通媒介。

* **Translation:** Refers to currency issued by the government and given legal tender status, not pegged to physical assets (e.g., gold). Compared to cryptocurrencies and other alternative currencies, fiat currency is the primary medium of exchange in the financial system.
* **Explanation:** This description highlights the position of fiat currency in relation to modern alternatives.

**Option 4: Slightly More Technical**

* **Description:** 依照政府的法律或規章發行的貨幣，並被政府宣布為合法支付方式。法定貨幣的價值由發行國政府的信用擔保，其供應量與利率等受央行管理和調控。

* **Translation:** Currency issued in accordance with government laws or regulations and declared by the government as a legal method of payment. The value of fiat currency is guaranteed by the credit of the issuing country’s government, and its supply and interest rates are managed and controlled by the central bank.
* **Explanation:** Provides a more in-depth explanation focusing on government guarantees and central bank influence.

**Recommendation:**

I recommend using **Option 2** or **Option 3** for your WordPress tag description. They offer a good balance of clarity, context, and relevance for most readers interested in finance or economics. Choose the one that best fits the overall tone and content of your website. Remember to save the description in the “Description” field of the post tag settings in your WordPress backend. Good luck!