Recommendations for the @xml:lang
    attribute
    
  
    Specifying the @xml:lang attribute in the
    DITA source facilitates translation and helps ensure that processors
    will handle content appropriately. Accordingly, this specification
    makes certain best-practices recommendations
    for where the @xml:lang attribute should be
    set.
Setting the @xml:lang attribute in the source-language document facilitates
      the translation process. Some translation tools do not support adding new markup to the
      document that is being translated, so if the source language content does not set the
        @xml:lang attribute, it might be difficult or impossible for a translator to
      add the @xml:lang attribute to the translated document.
In addition, setting the @xml:lang attribute in the
      DITA source ensures that processors handle content in a language- and
      locale-appropriate way. If the @xml:lang attribute is
      not set, processors might assume a default value which is
      inappropriate for the DITA content.
The following table outlines the recommended use of the @xml:lang attribute
      in topics and maps. These recommendations ensure that DITA resources have an effective default
      language.
| DITA resource | Recommended use | 
|---|---|
| DITA topic document that contains a single language | Specify the @xml:lang attribute on the root element of the
          document. | 
      
| DITA topic document that contains more than one language | Specify the primary language and locale that applies to
          the topic on the highest-level element that contains content. If
          part of a topic is written in a different language, enclose that
          content in an element with the @xml:lang
          attribute set appropriately. This
           applies
          to both block and inline elements that use the alternate
          language. | 
      
| DITA map | Specify the @xml:lang attribute on the
          root element of the map. This applies both to the root map and
          any submaps. |