[PHP] Important Design Patterns

[PHP Developer]

hello all,
As we know, there are a lot of php design patterns(more than 20). I want to 
know that which patterns are important and necessary for ZCE exam.
PHP5 Study Guide only covers Singleton,Factory,Registry,MVC and ActiveRecord. 
But i still feel that more patterns are necessary for the exam.
Cheers,
Daniel
 
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