This is a built-in template used for generate method +sharedInstance into class implementation section, e.g. when calling the Code | Generate | +sharedInstance function. The template is editable. Along with Objective-C expressions and comments, you can also use predefined variables that will be then expanded into the corresponding values.

Predefined variables will take the following values:
${$CLASS_TYPE}		name of the class where the method is implemented
All the predefined variables from the C File Header template (Includes tab) are also available (e.g. ${USER}, ${DATE}, etc.)