I have found some special symbols "#@+" and "#@-" in the comments/documentation in ZF1. Example:
/**#@+
* @access protected
*/
(https://github.com/zendframework/zf1/blob/master/library/Zend/Mail.php#L54)
I have seen before in another different repositories.
What do these mean?
They are PHP DocBlock templates declarations. There should be an ending tag /**#@-*/ in the file as well. It allows you to specify the same documentation across multiple properties, methods or constants.
A better explaination with examples can be found here: http://codingexplained.com/coding/php/how-to-use-docblock-templates-in-phpdoc