I have a project where I have documented options like so:
# @param [Hash] opts
# @option opts [NSColor] :colour (NSColor.magentaColor)
And the :colour option generates the following string in the web view:
:colour (NSColor) — default: NSColor.magentaColor —
I have not included any extra documentation for the :colour option but there is still a trailing "-" character. To me it looks strange and I think it would be better if it were note there.