Here are a few options for the description, ranging in detail and focus, for the WordPress post tag “信函撰寫” (Xìnhán Zhuànxiě – Letter Writing) in Traditional Chinese:

**Option 1 (Short & Sweet):**

> 掌握書信的藝術，學習如何撰寫專業、正式或私人的信函。 (Master the art of letters and learn how to write professional, formal, or personal correspondence.)

**Option 2 (More Informative):**

> 關於信函撰寫的一切！ 包含各種信件格式、文法技巧、常用詞彙，幫助您撰寫清晰、有效且符合不同情境的信件。 (Everything about letter writing! Includes various letter formats, grammar techniques, and common vocabulary, helping you write clear, effective, and contextually appropriate letters.)

**Option 3 (Emphasis on Purpose and Audience):**

> 探索信函撰寫的奧秘，無論是商務函件、求職信、感謝信或私人信件。學習如何根據不同的目的和收件人，選擇合適的語氣和風格，傳達您的信息。 (Explore the mysteries of letter writing, whether it’s business correspondence, cover letters, thank-you notes, or personal letters. Learn how to choose the appropriate tone and style, based on your purpose and recipient, to convey your message.)

**Option 4 (Focus on Practical Application):**

> 想寫出一封令人印象深刻的好信？ 從書信格式到內容安排，這裡提供實用的信函撰寫技巧與範例，幫助您在各種場合都能寫出得體的信件。 (Want to write a great letter that makes an impression? From letter format to content arrangement, we provide practical letter-writing skills and examples, helping you write appropriate letters in all kinds of situations.)

**Key Considerations when choosing:**

* **Target Audience:** Who is your blog geared towards? Choose a description that resonates with them.
* **Post Content:** What kind of posts will be tagged with this? Does it lean towards professional, personal, or general letter writing?
* **SEO:** Consider incorporating keywords related to letter writing in Chinese to improve search engine visibility. (e.g., “信件格式” (xìnjiàn géshì – letter format), “商務信函” (shāngwù xìnhán – business correspondence), etc.)

Choose the option that best fits your needs for the WordPress tag!