The highlighted Spot Slope references an element that is vertical.

Namespace: Autodesk.Revit.DB
Assembly: RevitAPI (in RevitAPI.dll) Version: 2015.0.0.0 (2015.0.0.0)

Syntax

C#
`public static FailureDefinitionId SpotSlopeReferenceIsVertical { get; }`

Visual Basic
`Public Shared ReadOnly Property SpotSlopeReferenceIsVertical As FailureDefinitionId Get`

Visual C++
`public: static property FailureDefinitionId^ SpotSlopeReferenceIsVertical { FailureDefinitionId^ get (); }`

See Also