[RCP-43] Local Fields and Predictability

[darnjo]

During the RESO Developer Conference, the group approved moving the following items forward for the proposal phase.

Discussed in #24

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Background

Local fields are important for extensibility. Providers currently have two ways they expose these items:

• By commingling local fields with existing standard resources; and
• Expanding local fields in from other resources.

The Data Dictionary already allows commingling of local fields with standard ones as long as they are truly local. Otherwise they must match the Data Dictionary.

What's needed is a convention for the standard name that local data elements are expanded in as to provide predictability.

Proposal

This proposal establishes a new standard field called "LocalData" as an expanded data element that can be added to any resource that supports it, such as Property, Member, etc.

The "LocalData" field will have a one-to-one relationship between the standard resource that includes it and the local resource data that's being expanded. In other words, CollectionYN is false.

The name of the resource that contains the local data is left to the provider's discretion, as the consumer can determine this (if needed) using the navigation property or Field Resource entry for the "LocalData" property.