27cm/ YoSD Size
All patterns in the 16cm (4") size fit 'YoSD' sized if you enlarge them 150%.
If you are sewing for both sizes, it's easier to get the small size and enlarge. Some 27cm patterns have been pre-enlarged for your convenience, and some patterns have more detail than can be put on a 16cm or 11cm doll so won't shrink well.
Note: Lots of doll companies call their dolls 'YoSD sized' but are not. Dolls in this size with wide hips (ex: 1/6 Imomo and 1/6 Tiny Fox) need Tiny Pear patterns.