What's a dotted slur?

[Bertalan Fodor]

Hello,

I'm looking at Ted Ross' book. It tells that: "some of the miscellaneous 
uses of the normal size dot is [...] ties, slurs"
To render something similar that is in the book, I need the attached 
fragment. Shouldn't it be the default for \slurDotted?
Ted Ross also uses these dots for Ottavas and other spanners.

\score {
   \new Staff {
       \relative c' {
      
       \once \override Voice.Slur #'thickness = #4.5
       \override Slur  #'dash-period = #0.9
       \override Slur #'dash-fraction = #0
       c4.( d e c8) }
}
}

\paper {
   raggedright = ##t
}