Does the preferred local setting include stockpiles?

Does the preferred local setting include getting items from stockpiles, or is that setting for internal manufacturing only? In other words, does the game make better use of stockpiles, with the ‘prefer local’ setting?

Hi Kris,
it looks like on the ‘prefer local’ setting every item should come form the manufactory direct.
I set it on allow everything, it looks like local product are also preferred but the stockpiles are in a better use. On the stockpiles i set it to just local to have a puffer for my local manufactory.