Knowledge Management display option question

In KM, there are a number of options at the top of an article, eg: Cancel, Edit, Add Feedback, Retire, Create Working Copy.

I want to remove the Create Working Copy one, but I cannot find where it is configured. If I look at the detail data for the screen, it tells me it's option 61.

  <option img="tcreate" value="61">
   <origcaption>Create Working Copy</origcaption>
   <caption>Create Working Copy</caption>
   <description>Create Working Copy</description>

However, there is no option 61 in display options for kmdocFlow.view (or indeed any option 61 in display options at all).  There is ony 'Create Working Copy' display option, but it's under the Screen ID of 'kmdocument.view' and it isn't the one being referenced when viewing a KM document.

Does anyone know where this is configured?