Here are a few options for a WordPress post tag description for the title “立案” (Lìàn) in Traditional Chinese, catering to different levels of formality and context:

**Option 1: Concise & General (Suitable for general blog posts)**

* **Description:** 案件開始立案。 (The case has initiated filing/reporting.)
* **Explanation:** This is a straightforward and easily understandable description of the process of filing a case or officially registering it.

**Option 2: Focused on Legal Matters**

* **Description:** 法律程序啟動，案件正式立案的階段。(The stage where legal procedures are initiated and a case is officially filed.)
* **Explanation:** This describes is specifically related to the legal process, clarifying it is the stage in which legal proceedings and investigation are intiated.

**Option 3: Emphasizing Investigation (More Specific)**

* **Description:** 立案後，調查工作隨即展開。 (Following filing/reporting, investigative work commences.)
* **Explanation:** If your blog discusses investigations or legal reporting, this clarifies that this process indicates the beginning of investigations.

**Option 4: Formal & Detailed (For more formal or legal blogs)**

* **Description:** 指案件經審核符合條件，正式登記並進入調查程序。 (Refers to when a case meets the required conditions, is officially registered, and enters the investigative process.)
* **Explanation:** This provides a more in-depth explanation of the process within the context of a law-related blog. It describes not just the act of filing, but also the relevant pre-filing procedure (reviewing requirements, etc.).

**Option 5: For a general audience related to topics like business, project planning**

* **Description:** 計畫、提案進入正式審核與啟動階段。 (Project or Proposal enters formal review and initiation phase.)
* **Explanation:** Instead of being a legal term, is used for business plans, startup plans, initiatives.

**To choose the best description:**

1. **Consider your blog’s topic:** Is it legal, general, social, or project management related?
2. **Think about your audience:** Are they experts, or a general audience?
3. **Keep it short and concise:** WordPress tags are best when kept brief.

When adding the description in your WordPress post editor, you might find it under the “Tags” or “Categories” section. There should be a field for adding a description when you edit/create a tag or category.