Here are a few options for the description of a WordPress post tag with the title “費用率” (Feiyonglv – Cost Ratio/Expense Ratio) in Traditional Chinese, catering to different levels of detail and audience:

**Option 1: Concise and Informative (General)**

> **簡介：** 費用率是指衡量企業或投資組合成本相對於收入、資產或投資額的比例。它反映了經營效率和投資管理效率。
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> **Translation/Explanation:**
> * **Brief:** The cost ratio is a measure of the cost of a company or investment portfolio relative to its revenue, assets, or investment amount. It reflects operational efficiency and investment management efficiency.

**Option 2: Slightly More Detail (Suitable for Financial/Business Context)**

> **簡介：** 「費用率」指在一定時間內，企業或投資組合所發生的費用，佔其收入、資產或投資額的百分比。 對企業而言，通常包括營運成本；對投資組合而言，則包括管理費、託管費等。 了解費用率有助於評估財務健康和投資績效。
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> **Translation/Explanation:**
> * **Brief:** “Cost Ratio” refers to the percentage of expenses incurred by a company or investment portfolio over a period of time, relative to its revenue, assets, or investment amount. For businesses, it typically includes operating costs; for investment portfolios, it includes management fees, custody fees, etc. Understanding the cost ratio helps assess financial health and investment performance.

**Option 3: Focusing on Application & SEO (Good for Blog Posts)**

> **簡介：** 了解「費用率」在您的企業或投資決策中扮演的角色！ 本標籤下的文章探討了各種費用率，包括營運費用率、股息收益率等，以及如何分析和改善這些指標，以提升盈利能力和投資回報。 我們也提供實用的建議，幫助您控制成本，實現財務目標。
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> **Translation/Explanation:**
> * **Brief:** Understand the role of the “Cost Ratio” in your business or investment decisions! Articles under this tag explore various cost ratios, including operating expense ratio, dividend yield, etc., and how to analyze and improve these indicators to enhance profitability and investment returns. We also provide practical advice to help you control costs and achieve your financial goals.

**Which option should you choose?**

* **Option 1:** Best for general audiences or if you want a simple, clear definition.
* **Option 2:** More appropriate for financial professionals, business owners, or those with some financial literacy.
* **Option 3:** Ideal for blog posts, allowing you to attract readers with specific interests and use keywords to optimize SEO. This option is particularly strong if you plan to write articles that delve into specific types of cost ratios and how to use them practically.

**Key Considerations:**

* **Target Audience:** Who are you writing for? Their level of financial understanding will impact the detail needed.
* **Blog Content:** What kinds of articles do you plan to write using this tag?
* **SEO:** Consider including related keywords like “營運成本” (operating costs), “投資績效” (investment performance), “股息收益率” (dividend yield) etc., to improve search engine visibility.

Remember to choose the description that best suits your overall blog purpose and your target audience. Good luck!