HelpMathLibrary
HelpMath displays xma.dec.

HelpStandardLibrary
HelpStandardLibrary displays xst.dec.

HelpGraphicsLibrary
HelpGraphicsDesigner displays xgr.dec.

HelpGuiDesignerLibrary
HelpGuiDesigner displays xui.dec.

HelpComplexNumberLibrary
HelpComplexNumber displays xcm.dec.