Under the rules for magic item creation these are the rules around prerequisites:
Note that all items have prerequisites in their descriptions. These prerequisites must be met for the item to be created. Most of the time, they take the form of spells that must be known by the item's creator (although access through another magic item or spellcaster is allowed). The DC to create a magic item increases by +5 for each prerequisite the caster does not meet. The only exception to this is the requisite item creation feat, which is mandatory. In addition, you cannot create potions, spell-trigger, or spell-completion magic items without meeting their spell prerequisites.
The bolded part is where my confusion comes in.
For example, belt of incredible dexterity states:
Craft Wondrous Item, cat's grace
Assuming I have a scroll of cat's grace there are 2 ways to read this.
I have the scroll but do not know the spell thus the DC of the item is +5 for a bypassed prerequisite.
I have the scroll which satisfies the requirement, as per the the bold above.
Which is it in RAW and subsequently, if it is 2 doesn't that mean that I can create the item without having the requisite spells?