Here, for example, is a part of the formal DTD for the register example given informally above.

<!ELEMENT register - - (entry+)>
<!ELEMENT entry - o (name, trade, relation?)>
<!ELEMENT name - - (#PCDATA)> 

These three lines are examples of SGML declarations: each defines or declares a name for an element and what its content should be. The details of the syntax need not detain us; note only that each declaration (like everything else in SGML) is explicitly delimited, in this case by a symbol marking the start of a declaration (the [“<!]”) (Burnard 1991, section 5.1).

Comments are closed.