on gate guardian,it says `this card can only be SPECIAL summoned by tributing....' it doesn't say that it can't be normal summoned.same thing with red eyes black metal dragon 'this card can only be SPECIAL summoned from THE DECK TO THE FIELD by tributing red eyes b dragon equipped with metalmorph. what do you say? :confused: :ermm:

This belongs in the rulings forum more. However I will answer it until it is moved.
Let's break down the card text. "This card can only be Special Summoned..." That itself should give you a hint that it can only be special summoned (now im starting to repeat myself in the same sentence...)
As well this is reinforced by UDE's rulings on this card text stating that these monsters must be originally special summoned first by that process. After they have been properly special summoned they can be special summoned from the graveyard by another method (ie. monster reborn). If the monster is properly special summoned by it's card effect and then returned to your hand you must special summon it properly again (properly being by the card text).

Any Questions?