[2WS-Steve]

Originally Posted by GMSkarka

The FATE system which powers Spirit of the Century is 100% Open, and an SRD is available.

I had thought that too, but it seems the Product Identity designation (found at the bottom) is:

Originally Posted by SotC SRD

For purposes of this license, the following things are considered to be Product Identity in addition to anything covered in section 1, above:

The bolded part refers to:

Originally Posted by OGL

“Product Identity” means product and product line names, logos and identifying marks including trade dress; artifacts; creatures characters; stories, storylines, plots, thematic elements, dialogue, incidents, language, artwork, symbols, designs, depictions, likenesses, formats, poses, concepts, themes and graphic, photographic and other visual or audio representations; names and descriptions of characters, spells, enchantments, personalities, teams, personas, likenesses and special abilities; places, locations, environments, creatures, equipment, magical or supernatural abilities or effects, logos, symbols, or graphic designs; and any other trademark or registered trademark clearly identified as Product identity by the owner of the Product Identity, and which specifically excludes the Open Game Content;

Which, according to the license, would mean that any supplement you write couldn't refer to the stunt names in the core rules, their descriptions, equipment names/descriptions, I take it aspects, and probably a lot more.

It's basically a "anything that can be declared PI, is PI" designation, which typically makes the open content useless since all that's left behind are some numbers and whatever open content was used from previous sources.