In a DTD, how does one say that an attribute must exist in the XML document?( )
add #REQUIRED to DTD
add #IMPLIED to DTD
add #PCDATA to DTD
add comment to DTD
青云测评
青云测评
In a DTD, how does one say that an attribute must exist in the XML document?( )
add #REQUIRED to DTD
add #IMPLIED to DTD
add #PCDATA to DTD
add comment to DTD
