#27899

is a custom JSP tag, which works only in JSP container. Its attributes are mapped to PD4ML API calls. So in .JSP implicitly invokes pd4ml.setPageInsetsMM(new Insets(10, 30, 20, 20));

If you do not use PD4ML JSP taglib, a call like pd4ml.setPageInsetsMM(new Insets(10, 30, 20, 20)); is the only way to define the margins.