Proposed resolution:

This wording is relative to N4981.

1. Modify [facet.num.put.virtuals] as indicated:

   Table 114 – Floating-point conversions [tab:facet.num.put.fp]

   State	`stdio` equivalent
   `floatfield == ios_base::fixed` && !uppercase	`%f`
   `floatfield == ios_base::fixed`	`%F`
   floatfield == ios_base::scientific && !uppercase	`%e`
   floatfield == ios_base::scientific	`%E`
   floatfield == (ios_base::fixed | ios_base::scientific)` && !uppercase	`%a`
   floatfield == (ios_base::fixed | ios_base::scientific)	`%A`
   `!uppercase`	`%g`
   otherwise	`%G`