title: Strange type definition syntax in Golang (name, then type, then string literal)
body: <p>I've been trying to find out how to use mgo (MongoDB driver for Go) and I came across this struct declaration:</p>
  
  <pre><code>type Something struct {
      Id bson.ObjectId "_id,omitempty"
      Name string
  }
  </code></pre>
  
  <p>I don't quite understand the syntax of the first element (Id).  I understand that it's being declared as type <code>bson.ObjectId</code>, but what is the string literal doing there?</p>
  
  <p>My question is not about the mgo driver functionality,<br>
  but about this strange <code>&lt;name&gt; &lt;type&gt; &lt;string_literal&gt;</code> syntax.</p>
  
  <p>I couldn't find anything on the Go specs, and I don't know how to google this either.</p>