Upon the addition of a Parameter object to an SBMLDocument object (e.g., using the method Model::addParameter()), the @p level, @p version, and @p xmlns namespaces for the document @em override those used to create the Parameter. Despite this, the ability to supply the values at creation time is an important aid to creating valid SBML. Knowledge of the intented SBML Level and Version determine whether it is valid to assign a particular value to an attribute, or whether it is valid to add an object to an existing SBMLDocument.