[oXygen-user] docbook variable substitution

Hi, Apologies if this is slightly off topic. I have a docbook question. Is there a way to define a variable in docbook and reference it in the text? In latex I would do: "\newcommand{\book}{Gone With the Wind}" then in the text: "I recently read \book." which would render as "I recently read Gone With the Wind." I can't seem to find out if this is possible. Thanks in advance. Andrew