ZF-8303: Zend_Form_Decorator_Fieldset generated id is not similar with the rest of id's used on form decorators
That's just a naming convention, but id's generated by fieldset decorator are looking like that:
fieldset-name. So the element name is appended
Instead of this the rest of decorators are actually prepending the name of the element:
name-element name-label aso.
That's just a small naming convention mistake, but should be fixed anyway...