title: Kohana ORM "primary value"
body: <p>I've been reading through the documentation for Kohana ORM and in their example model class it has a block of code like:</p>
  
  <pre><code>protected $_table_name  = 'strange_tablename'; // default: accounts
  protected $_primary_key = 'strange_pkey';      // default: id
  protected $_primary_val = 'strange_name';      // default: name (column used as primary value)
  </code></pre>
  
  <p>Obviously I know what table name and primary key are but I've never seen the term "primary value" used before, what exactly is it used for?</p>