icon in front of URL

png, jpg, gif，後面加上 type="image/png"、type="image/jpg"、type="image/gif"
png語法:     <link rel="icon" href="圖片網址" type="image/png" />
jpg語法:      <link rel="icon" href="圖片網址" type="image/jpg" />
gif語法:        <link rel="icon" href="圖片網址" type="image/gif" />

icon檔：
<link rel="SHORTCUT ICON" href="圖片網址"/>
<link rel="icon" href="圖片網址" type="image/ico" />