Name	Data Type	Definition
type	CodeHoldingUsageType	An indicator of the type of holding procedure (e.g., en-route holding, terminal area holding).
outboundCourse	ValBearingType	The outbound course (for example, true track, magnetic track, heading, VOR radial, true bearing, magnetic bearing) from the facility or waypoint on which holding is based.
outboundCourseType	CodeCourseType	The type of outbound course to be observed (for example, true track, magnetic track, heading, VOR radial, true bearing, magnetic bearing) on which holding is based.
inboundCourse	ValBearingType	The radial, course or bearing of the inbound leg as it pertains to a holding pattern.
turnDirection	CodeDirectionTurnType	An indicator of the turn direction (such as left, right or either) in an aerial manoeuvre performed by aircraft during holding operations.
upperLimit	ValDistanceVerticalType	The maximum vertical distance (measured from a specified reference) allowed for all aircraft categories, at all defined speeds, operating in a holding pattern.
upperLimitReference	CodeVerticalReferenceType	The reference surface (Mean Sea Level, Ground, standard pressure, etc.) used for determining the value of the upper limit of a holding pattern.
lowerLimit	ValDistanceVerticalType	The minimum vertical distance (measured from a specified reference) allowed for all aircraft categories, at all defined speeds, operating in a holding pattern.
lowerLimitReference	CodeVerticalReferenceType	The reference surface (Mean Sea Level, Ground, standard pressure, etc.) used for determining the value of the lower limit of a holding pattern.
speedLimit	ValSpeedType	Restricted speed for containment in a smaller pattern during holding operations.
instruction	TextInstructionType	Operational instructions that must be observed when flying the holding pattern.
nonStandardHolding	CodeYesNoType	An indication that the holding pattern is non-standard (for example, because it uses left-hand turns).

Association	Multiplicity	Role	To	Role description
isDepictedBy	0..1	extent	Curve	The geographical curve depicted as a race track pattern
hasSpan	0..1	outboundLegSpan	HoldingPatternLength	Outbound leg ends at a choice of a time, a length or a defined end point.
hasAnnotations	0..*	annotation	Note
isBasedOn	0..1	holdingPoint	SegmentPoint	The point used to define the holding pattern.

From	Association	Multiplicity	Role	To	Role description
InformationService	concerns	0..*	clientHolding	The holding pattern for which the information is provided.
HoldingAssessment	determines	0..1	assessedHoldingPattern	The HoldingPattern assessed by the HoldingAssessment.
SegmentLeg	establishes	0..1	holding	Established holding used on a procedure.
AirTrafficControlService	controls	0..*	clientHolding	The Holding Pattern on which the air traffic control is provided.

1 - Holding Pattern , 2 - Unplanned Holding , 3 - Segment Leg , 4 - Information Service , 5 - Air Traffic Control Services