# Grasshopper2.Data.Meta namespace

Assembly: [Grasshopper2](https://developer.rhino3d.com/api/gh2/assembly/grasshopper2.md)

## Enums

- [Material](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.material.md): Enumerates the internally defined standard materials.
- [MergeBehaviour](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.mergebehaviour.md): Enumerates the possible merging behaviour of meta data structures.
- [MetaDataComparison](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.metadatacomparison.md): The various outcomes when comparing meta data values.
- [MetaType](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.metatype.md): Enumerates the possible types of meta data.
- [Operator](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.operator.md): Enumerates the possible comparison operators between meta data values and constants.
- [TransientMetaData](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.transientmetadata.md): Enumerates all standard meta data entries considered 'transient', i.e. data which oughtn't be copied to offspring data.

## Classes

- [MetaData](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.metadata.md): Represents an unbounded collection of meta data.
- [MetaData.MetaDataValidationEventArgs](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.metadata.metadatavalidationeventargs.md): Event arguments used during meta data validation.
- [MetaDataExtensions](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.metadataextensions.md): A set of extension methods for [MetaData](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.metadata.md).
- [MetaDataList](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.metadatalist.md): A list of unique metadata instances.
- [MetaName](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.metaname.md): Represents an immutable data name. We recommend not constructing new names all the time, but instead to have a collection of static names which are used over and over again. This will both result in performance increases and fewer naming mistakes.
- [MetaValue](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.metavalue.md): Represents a meta data value. This is really just a wrapper class around all the supported meta data value types so we don't have to use 'object' to store meta data.
- [StandardNames](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.standardnames.md): Defines the set of meta data keys used by Grasshopper.
- [StandardNames.Annotation](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.standardnames.annotation.md): Collection of standard meta data names associated with annotation and dimensioning.
- [StandardNames.Data](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.standardnames.data.md): Collection of standard meta data names associated with structured data storage.
- [StandardNames.Display](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.standardnames.display.md): Collection of standard meta data keys associated with display overrides.
- [StandardNames.Physics](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.standardnames.physics.md): Collection of standard meta data keys associated with physical properties of objects.
- [StandardNames.Record](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.standardnames.record.md): Collection of standard meta data keys associated with record and bookkeeping data.
- [StandardNames.Rhino](https://developer.rhino3d.com/api/gh2/type/grasshopper2.data.meta.standardnames.rhino.md): Collection of standard meta data keys associated with Rhino interaction.