Toplevel_commentsA doc comment at the beginning of a module is considered to be that module's doc.
      module 
       type 
       T
      
       = sig ... 
       end
      
     
    Doc of T, part 1.
      module 
       Include_inline
      
       : sig ... 
       end
      
     
    Doc of T, part 2.
      module 
       Include_inline'
      
       : sig ... 
       end
      
     
    Doc of Include_inline, part 1.
      module 
       type 
       
        Include_inline_T
       
      
       = sig ... 
       end
      
     
    Doc of T, part 2.
      module 
       type 
       
        Include_inline_T'
       
      
       = sig ... 
       end
      
     
    Doc of Include_inline_T', part 1.
      module 
       M
      
       : sig ... 
       end
      
     
    Doc of M
      module 
       M'
      
       : sig ... 
       end
      
     
    Doc of M' from outside
      module 
       M''
      
       : sig ... 
       end
      
     
    Doc of M'', part 1.
class 
      c1
       : int -> 
       object ... 
       end
      
     
    Doc of c1, part 1.
      class 
       type  
      
      ct
       = object ... 
       end
      
     
    Doc of ct, part 1.
      module 
       Ref_in_synopsis
      
       : sig ... 
       end
      
     
    
      t
      .
     
      module 
       Comments_on_open
      
       : sig ... 
       end