Here are a few options for a WordPress post_tag description for “里程” (miles/mileage) in Traditional Chinese, each with a slightly different slant:

**Option 1 (Simple & Direct):**

* **Description:** 代表行駛距離的單位。通常用公里 (km) 或英里 (mi) 呈現。 (Describes units of distance traveled. Often expressed in kilometers (km) or miles (mi).)

**Option 2 (Focus on Context – Cars/Travel):**

* **Description:** 描述車輛行駛的距離或旅行的路程。包含里程表讀數、旅行總里程等。 (Describes the distance a vehicle has traveled or the journey undertaken. Includes odometer readings, total travel distance, etc.)

**Option 3 (More Detailed):**

* **Description:** 指物體行進的長度，可以用於衡量交通工具的行程，例如汽車、火車或飛機的行駛距離。也可用來表示徒步旅行或騎自行車的距離。 (Refers to the length traveled by an object, and can be used to measure the distance traveled by vehicles such as cars, trains, or airplanes. Also can indicate the distance of hikes or cycling.)

**Option 4 (Focus on Digital Context – Useful in websites related to travel or maps):**

* **Description:** 網站中與距離相關的關鍵詞。用於標記地圖上的距離，或旅行報告中的行程。 (Keyword related to distance on a website. Used to tag the distance on a map or travel log.)

**Why these are good:**

* **Clear & Concise:** Each option provides a clear explanation of what “里程” means.
* **Focus on Context:** The options subtly gear the description toward the intended audience and potential uses of the tag.
* **Uses appropriate vocabulary:** Uses effective words in Tradional Chinese to make it understandable and relevant.
* **SEO friendly:** Keywords that will attract users searching for this topic.

When choosing, consider the overall theme and content of your WordPress site to pick the best fit. You can also adjust these or combine components to best suit *your* needs.