看golang html包中的escape.go 文件会发现有个这样的定义

var htmlEscaper = strings.NewReplacer(
    `&`, "&",
    `'`, "'", // "'" is shorter than "'" and apos was not in HTML until HTML5.
    `<`, "&lt;",
    `>`, "&gt;",
    `"`, "&#34;", // "&#34;" is shorter than "&quot;".
)

其中使用到 `` 语法, 目前理解应该是不转义纯字符串的意思