Course Catalog DTD examples

course_catalog_1.dtd

<!DOCTYPE Course_Catalog [
<!ELEMENT Course_Catalog (Department+)>
<!ELEMENT Department (Title,Course*,Professor*,Lecturer*)>
<!ELEMENT Professor (First_Name,Middle_Initial?,Last_Name)>
<!ELEMENT Lecturer (First_Name,Middle_Initial?,Last_Name)>
<!ELEMENT Course (Title,Description?)>
<!ELEMENT Description (#PCDATA | Courseref)*>
<!ELEMENT Courseref EMPTY>
<!ELEMENT Title (#PCDATA)>
<!ELEMENT First_Name (#PCDATA)>
<!ELEMENT Middle_Initial (#PCDATA)>
<!ELEMENT Last_Name (#PCDATA)>

<!ATTLIST Department Chair CDATA #REQUIRED>
<!ATTLIST Department Code ID #REQUIRED>
<!ATTLIST Course Enrollment CDATA #IMPLIED>
<!ATTLIST Course Instructors CDATA #REQUIRED>
<!ATTLIST Course Number ID #REQUIRED>
<!ATTLIST Course Prerequisites CDATA #IMPLIED>
<!ATTLIST Courseref Number IDREF #REQUIRED>
<!ATTLIST Professor InstrID ID #REQUIRED>
<!ATTLIST Lecturer InstrID ID #REQUIRED>
]>

course_catalog_2.dtd

<!DOCTYPE Course_Catalog [
<!ELEMENT Course_Catalog (Department+)>
<!ELEMENT Department (Title,Chair,Course*)>
<!ELEMENT Chair (Professor)>
<!ELEMENT Professor (First_Name,Middle_Initial?,Last_Name)>
<!ELEMENT Course (Title,Instructors,Prerequisites?)>
<!ELEMENT Prerequisites (Prereq+)>
<!ELEMENT Instructors (Lecturer*,Professor*)>
<!ELEMENT Lecturer (First_Name,Middle_Initial?,Last_Name)>
<!ELEMENT Title (#PCDATA)>
<!ELEMENT First_Name (#PCDATA)>
<!ELEMENT Middle_Initial (#PCDATA)>
<!ELEMENT Last_Name (#PCDATA)>
<!ELEMENT Prereq (#PCDATA)>
<!ELEMENT Description (#PCDATA)>

<!ATTLIST Department Code ID #REQUIRED>
<!ATTLIST Course Enrollment CDATA #IMPLIED>
<!ATTLIST Course Number ID #REQUIRED>
]>