This is significant because all previous iOS resources attempting this level of detail have been created by the design community. A designer named Joey Banks created widely adopted UI Kits for iOS 13-16[1]. Earlier iOS resources were created by an agency called Teehan+Lax[2] and some others I’m forgetting now.

All community-created design resources have historically been really good best guesses. Now they’re available directly from Apple.

Apple is letting design teams reveal what’s happening on the inside a little bit and this is one example.

[1] https://www.figma.com/@joey [2] https://teehanlax.com/tools/