<!ELEMENT ADDRBOOK (ENTRY*)>
<!ELEMENT ENTRY (NAME, ADDRESS, PHONENUM*, EMAIL)>
<!ATTLIST ENTRY
    ID ID #REQUIRED
>
<!ELEMENT NAME (#PCDATA)>
<!ELEMENT ADDRESS (#PCDATA)>
<!ELEMENT PHONENUM (#PCDATA)>
<!ATTLIST PHONENUM
    DESC CDATA #REQUIRED
>
<!ELEMENT EMAIL (#PCDATA)>
