A note on the Metadata property

The C# EcsDocument type includes a property called Metadata with the signature:

 /// <summary> /// Container for additional metadata against this event. /// </summary> [JsonPropertyName("metadata"), DataMember(Name = "metadata")] public IDictionary<string, object> Metadata { get; set; } 

This property is not part of the ECS specification, but is included as a means to index supplementary information.