If $oxy-markup is true, then the change tracking processing instructions that Oxygen inserts into the document will be transformed into elements marked with CSS classes for rendering in the output. See $oxy-markup-css.

Rendering Oxygen change markup can be specified on a document-by-document bases with a db processing instruction. If the oxy-markup pseudo-attribute is true, the markup will be rendered. This processing instruction must be in the info element of the document element.