Here are a few options for describing the WordPress post_tag “加購” (Jiāgòu) in Traditional Chinese, catering to different audiences and purposes:

**Option 1: Concise and Direct**

* **Description:** 凡購買其他產品時，可選擇加購的選項。
* **Translation:** Items available for addition to your order, purchased alongside other products.
* **Best for:** Straightforward explanation, easily understood by most users.

**Option 2: Explanatory and Engaging**

* **Description:** 選購完主要商品後，不妨看看我們的加購專區！這裡有各種優惠組合，讓您搭配心儀的商品，享受更多驚喜。
* **Translation:** After selecting your main items, why not browse our “Add-on” section! Here you’ll find various promotional bundles to complement your chosen products and enjoy more surprises.
* **Best for:** Encouraging customers to explore the extras, highlighting potential benefits.

**Option 3: Technical with a hint of Customer-centricity**

* **Description:** 表明此商品為加購品項。提供選購時，消費者可額外選購的非必要性產品。
* **Translation:** Indicates that this product is an add-on item. Provides consumers with optional products to purchase in addition to their primary selections.
* **Best for:** Developers/Administrators working on the site, provides a functional understanding, with an awareness of the customer experience.

**Option 4: Focus on saving money (if applicable)**

* **Description:** 超值加購優惠！搭配主商品，以更優惠的價格將商品帶回家。
* **Translation:** Amazing add-on deals! Combine with the main products, and bring home the goods at better prices.
* **Best for:** Highlighting the value to increase sales.

**Key Considerations when choosing your description:**

* **Target Audience:** Who is most likely to see and use this tag? (e.g., regular customers, website admins, etc.)
* **Purpose:** Does the description need to be purely functional, promotional, or both?
* **Context:** How is this tag used within the WordPress site? Is it part of a navigation menu? Used within a product filter?

Choose the option that best suits your needs and remember to translate the description in Wordpress. Good luck!