How units are displayed

Unitful.abbr
Unitful.prefix
Unitful.show(::IO, ::Quantity)
Unitful.show{T,D,U}(::IO, ::Type{Quantity{T,D,U}})
Unitful.show(::IO,::Unitful.Unitlike)
Unitful.showrep(::IO,::Unitful.Unit)
Unitful.showrep(::IO,::Unitful.Dimension)
Unitful.superscript