San Francisco (sans-serif typeface) and iOS 10 is a new variant named "SF Compact Rounded". It is used in the new contact placeholder icons introduced in the OSes. The "SF Serif" variant was showcased during the keynote at WWDC 2018 on June 4, 2018 when the all-new Apple Books app was introduced. This variant is exclusive to Apple Books in iOS 12 and macOS Mojave, is not mentioned in Apple's Typography design guidelines, and is not publicly downloadable like other variants of the San Francisco typeface. Since its introduction, San Francisco has gradually replaced most of Apple's other typefaces on their software and hardware
Thibaudeau classification serifs. It corresponds to the three classical categories (humanists, garaldes and transitionals) from the Vox-ATypI classification. Examples: Garamond, Palatino, Times Roman This family groups typefaces with linear or hairline serifs. It generally corresponds to modern or Didone categories. Examples: Didot, Bodoni, Walbaum Roman This family contains slab serif typefaces, called Mechanistic in the Vox-ATypI classification. Examples: Memphis, Rockwell This is the sans serif family. In Vox-ATypI classification, this family corresponds to the Lineals. Examples: Futura, Univers, Arial, Helvetica... Thibaudeau classification In typography, the Thibaudeau Classification is a way to group typefaces into four general families, according to shape and serif