Internally, a shape type is defined as a fixed set of property values, the most important being the geometry of the shape (the pVertices property, etc.). Each shape stores in itself only those properties that differ from its shape type. When a shape is asked for a property that isn't in its local table, it looks in the shape type's table. If the shape type doesn't define a value for the property, then the property's default value is used.
In the file format, shapes store their shape types in the instance field of the msofbtSp record.
typedef enum
{
msosptMin = 0,
msosptNotPrimitive = msosptMin,
msosptRectangle = 1,
msosptRoundRectangle = 2,
msosptEllipse = 3,
msosptDiamond = 4,
msosptIsocelesTriangle = 5,
msosptRightTriangle = 6,
msosptParallelogram = 7,
msosptTrapezoid = 8,
msosptHexagon = 9,
msosptOctagon = 10,
msosptPlus = 11,
msosptStar = 12,
msosptArrow = 13,
msosptThickArrow = 14,
msosptHomePlate = 15,
msosptCube = 16,
msosptBalloon = 17,
msosptSeal = 18,
msosptArc = 19,
msosptLine = 20,
msosptPlaque = 21,
msosptCan = 22,
msosptDonut = 23,
msosptTextSimple = 24,
msosptTextOctagon = 25,
msosptTextHexagon = 26,
msosptTextCurve = 27,
msosptTextWave = 28,
msosptTextRing = 29,
msosptTextOnCurve = 30,
msosptTextOnRing = 31,
msosptStraightConnector1 = 32,
msosptBentConnector2 = 33,
msosptBentConnector3 = 34,
msosptBentConnector4 = 35,
msosptBentConnector5 = 36,
msosptCurvedConnector2 = 37,
msosptCurvedConnector3 = 38,
msosptCurvedConnector4 = 39,
msosptCurvedConnector5 = 40,
msosptCallout1 = 41,
msosptCallout2 = 42,
msosptCallout3 = 43,
msosptAccentCallout1 = 44,
msosptAccentCallout2 = 45,
msosptAccentCallout3 = 46,
msosptBorderCallout1 = 47,
msosptBorderCallout2 = 48,
msosptBorderCallout3 = 49,
msosptAccentBorderCallout1 = 50,
msosptAccentBorderCallout2 = 51,
msosptAccentBorderCallout3 = 52,
msosptRibbon = 53,
msosptRibbon2 = 54,
msosptChevron = 55,
msosptPentagon = 56,
msosptNoSmoking = 57,
msosptSeal8 = 58,
msosptSeal16 = 59,
msosptSeal32 = 60,
msosptWedgeRectCallout = 61,
msosptWedgeRRectCallout = 62,
msosptWedgeEllipseCallout = 63,
msosptWave = 64,
msosptFoldedCorner = 65,
msosptLeftArrow = 66,
msosptDownArrow = 67,
msosptUpArrow = 68,
msosptLeftRightArrow = 69,
msosptUpDownArrow = 70,
msosptIrregularSeal1 = 71,
msosptIrregularSeal2 = 72,
msosptLightningBolt = 73,
msosptHeart = 74,
msosptPictureFrame = 75,
msosptQuadArrow = 76,
msosptLeftArrowCallout = 77,
msosptRightArrowCallout = 78,
msosptUpArrowCallout = 79,
msosptDownArrowCallout = 80,
msosptLeftRightArrowCallout = 81,
msosptUpDownArrowCallout = 82,
msosptQuadArrowCallout = 83,
msosptBevel = 84,
msosptLeftBracket = 85,
msosptRightBracket = 86,
msosptLeftBrace = 87,
msosptRightBrace = 88,
msosptLeftUpArrow = 89,
msosptBentUpArrow = 90,
msosptBentArrow = 91,
msosptSeal24 = 92,
msosptStripedRightArrow = 93,
msosptNotchedRightArrow = 94,
msosptBlockArc = 95,
msosptSmileyFace = 96,
msosptVerticalScroll = 97,
msosptHorizontalScroll = 98,
msosptCircularArrow = 99,
msosptNotchedCircularArrow = 100,
msosptUturnArrow = 101,
msosptCurvedRightArrow = 102,
msosptCurvedLeftArrow = 103,
msosptCurvedUpArrow = 104,
msosptCurvedDownArrow = 105,
msosptCloudCallout = 106,
msosptEllipseRibbon = 107,
msosptEllipseRibbon2 = 108,
msosptFlowChartProcess = 109,
msosptFlowChartDecision = 110,
msosptFlowChartInputOutput = 111,
msosptFlowChartPredefinedProcess = 112,
msosptFlowChartInternalStorage = 113,
msosptFlowChartDocument = 114,
msosptFlowChartMultidocument = 115,
msosptFlowChartTerminator = 116,
msosptFlowChartPreparation = 117,
msosptFlowChartManualInput = 118,
msosptFlowChartManualOperation = 119,
msosptFlowChartConnector = 120,
msosptFlowChartPunchedCard = 121,
msosptFlowChartPunchedTape = 122,
msosptFlowChartSummingJunction = 123,
msosptFlowChartOr = 124,
msosptFlowChartCollate = 125,
msosptFlowChartSort = 126,
msosptFlowChartExtract = 127,
msosptFlowChartMerge = 128,
msosptFlowChartOfflineStorage = 129,
msosptFlowChartOnlineStorage = 130,
msosptFlowChartMagneticTape = 131,
msosptFlowChartMagneticDisk = 132,
msosptFlowChartMagneticDrum = 133,
msosptFlowChartDisplay = 134,
msosptFlowChartDelay = 135,
msosptTextPlainText = 136,
msosptTextStop = 137,
msosptTextTriangle = 138,
msosptTextTriangleInverted = 139,
msosptTextChevron = 140,
msosptTextChevronInverted = 141,
msosptTextRingInside = 142,
msosptTextRingOutside = 143,
msosptTextArchUpCurve = 144,
msosptTextArchDownCurve = 145,
msosptTextCircleCurve = 146,
msosptTextButtonCurve = 147,
msosptTextArchUpPour = 148,
msosptTextArchDownPour = 149,
msosptTextCirclePour = 150,
msosptTextButtonPour = 151,
msosptTextCurveUp = 152,
msosptTextCurveDown = 153,
msosptTextCascadeUp = 154,
msosptTextCascadeDown = 155,
msosptTextWave1 = 156,
msosptTextWave2 = 157,
msosptTextWave3 = 158,
msosptTextWave4 = 159,
msosptTextInflate = 160,
msosptTextDeflate = 161,
msosptTextInflateBottom = 162,
msosptTextDeflateBottom = 163,
msosptTextInflateTop = 164,
msosptTextDeflateTop = 165,
msosptTextDeflateInflate = 166,
msosptTextDeflateInflateDeflate = 167,
msosptTextFadeRight = 168,
msosptTextFadeLeft = 169,
msosptTextFadeUp = 170,
msosptTextFadeDown = 171,
msosptTextSlantUp = 172,
msosptTextSlantDown = 173,
msosptTextCanUp = 174,
msosptTextCanDown = 175,
msosptFlowChartAlternateProcess = 176,
msosptFlowChartOffpageConnector = 177,
msosptCallout90 = 178,
msosptAccentCallout90 = 179,
msosptBorderCallout90 = 180,
msosptAccentBorderCallout90 = 181,
msosptLeftRightUpArrow = 182,
msosptSun = 183,
msosptMoon = 184,
msosptBracketPair = 185,
msosptBracePair = 186,
msosptSeal4 = 187,
msosptDoubleWave = 188,
msosptActionButtonBlank = 189,
msosptActionButtonHome = 190,
msosptActionButtonHelp = 191,
msosptActionButtonInformation = 192,
msosptActionButtonForwardNext = 193,
msosptActionButtonBackPrevious = 194,
msosptActionButtonEnd = 195,
msosptActionButtonBeginning = 196,
msosptActionButtonReturn = 197,
msosptActionButtonDocument = 198,
msosptActionButtonSound = 199,
msosptActionButtonMovie = 200,
msosptHostControl = 201,
msosptTextBox = 202,
msosptMax,
msosptNil = 0x0FFF,
} MSOSPT;