關於「usps postcard size」標籤，搜尋引擎有相關的訊息討論：

Sizes for Postcards | Postal Explorer - USPSIf your mailpiece does not meet the dimensions above, then the Postal Service considers it a letter and letter-size postage is charged. With USPS Marketing Mail ...缺少字詞： gl= tw圖片全部顯示What is the Right Size For Your Direct Mailpiece |