Problem with private variable declaration syntax

The 2019 LRM syntax for private variable allows to declare a "private shared variable" which is clearly wrong.

private_variable_declaration ::= [§ 5.6.2]
  private variable_declaration


variable_declaration ::= [§ 6.4.2.4]
  [ shared ] variable identifier_list : subtype_indication [ generic_map_aspect ]
     [ := conditional_expression ] ;