As of Version 8, PrincipalComponents is part of the built-in Mathematica kernel.
As of Version 6.0, NotationBoxTag has been superseded by "NotationTemplateTag" and by ParsedBoxWrapper.
As of Version 6.0, NotationMadeBoxesTag has been superseded by "NotationMadeBoxesTag" and by ParsedBoxWrapper.
As of Version 6.0, NotationPatternTag has been superseded by "NotationPatternTag".
PieChart
(Obsolete Pie Charts Package Symbol) As of Version 7.0, PieChart is part of the built-in Mathematica kernel.
As of Version 7.0, PieEdgeStyle has been superseded by ChartStyle.
As of Version 7.0, PieExploded has been superseded by SectorSpacing.
PieLabels
(Obsolete Pie Charts Package Symbol) As of Version 7.0, PieLabels has been superseded by ChartLabels.