san francisco

There appears to be some strange internal doublethink going on with the bundled version of San Francisco.

Indeed, like all core fonts, it's located in /System/Library/Fonts, and it occupies a handful of files prefixed "SFNS." But it doesn't show up anywhere in Font Book, as far as I could see. And if you go to re-"install" it (File: Add Fonts and select those files), it will happily copy the files out of the system folder into ~/Library/Fonts——but will still absolutely refuse to show it in the font list!

Whatever the reasoning behind this, it's totally creeping me out.

(note that the same font—the same files, AFAICT—can be downloaded from Apple directly, but have the prefix "SanFrancisco" instead of "SFNS.")

OK, I downloaded the official Watch package, including the public-facing font files, and they behave—interestingly, as well.

Opening those font files from the Finder should (and does, in Yosemite) open a font preview window in Font Book. In 10.11, the SanFrancisco* files behave the same as the SFNS* ones in this case: Font Book completely ignores them. And again, going to File: Add Fonts allows you to select the files, and they do get copied into the right directory. The only difference is that they then become visible to applications, including Font Book, TextEdit, etc.

My best guess is that SFNS* are tagged the same way LastResort.ttf is, to be internally available and displayable, but otherwise unavailable to the user.

For something as critical as the standard interface font, this seems extremely cowardly and proprietary, and moreover totally a useless distinction.

SFNS and SFUI, for OS X and iOS respectively, differ slightly from the San Francisco font downloadable from the watchOS resources page.

This is from the license agreement that came along with the watch resources download originally:

IMPORTANT NOTE: THE APPLE SAN FRANCISCO FONT IS TO BE USED SOLELY FOR PURPOSES OF DESIGN AND DEVELOPMENT OF APPLICATIONS FOR APPLE WATCH.