Driven by current analysis of JSON-LD in the GeoJSON community, I kindly suggest we investigate how JSON-LD (A JSON-based Serialization for Linked Data) might be mixed into OData JSON to avoid interoperability problems when our annotation and referencing style meets the "@" key culture of JSON-LD.
Writing while thinking about it: Maybe a vocabulary might enable aliasing of the keys for JSON-LD overlapped concepts?
Citing the content of JSON-LD 3.3 "Syntax Tokens and Keywords" to go "in medias res":
JSON-LD specifies a number of syntax tokens and keywords that are a core part of the language:
Used to define the short-hand names that are used throughout a JSON-LD document.
These short-hand names are called terms and help developers to express specific identifiers in a compact manner.
The @context keyword is described in detail in section 5.1 The Context.
Used to uniquely identify things that are being described in the document with IRIs or blank node identifiers.
This keyword is described in section 5.3 Node Identifiers.
Used to specify the data that is associated with a particular property in the graph.
This keyword is described in section 6.9 String Internationalization and section 6.4 Typed Values.
Used to specify the language for a particular string value or the default language of a JSON-LD document.
This keyword is described in section 6.9 String Internationalization.
Used to set the data type of a node or typed value. This keyword is described in section 6.4 Typed Values.
Used to set the default container type for a term. This keyword is described in section 6.11 Sets and Lists.
Used to express an ordered set of data. This keyword is described in section 6.11 Sets and Lists.
Used to express an unordered set of data and to ensure that values are always represented as arrays.
This keyword is described in section 6.11 Sets and Lists.
Used to express reverse properties. This keyword is described in section 6.12 Reverse Properties.
Used to specify that a container is used to index information and that processing should continue deeper into a JSON data structure.
This keyword is described in section 6.16 Data Indexing.
Used to set the base IRI against which relative IRIs are resolved. This keyword is described in section 6.1 Base IRI.
Used to expand properties and values in @type with a common prefix IRI. This keyword is described in section 6.2 Default Vocabulary.
Used to express a graph. This keyword is described in section 6.13 Named Graphs.
The separator for JSON keys and values that use compact IRIs.
All keys, keywords, and values in JSON-LD are case-sensitive.
citation source at URL=http://www.w3.org/TR/json-ld/#syntax-tokens-and-keywords
The decorated IRI terms are described non-normatively e.g.. in section 6.1 for compact IRI:
A compact IRI is a way of expressing an IRI using a prefix and suffix separated by a colon (. The prefix is a term taken from the active context and is a short string identifying a particular IRI in a JSON-LD document. For example, the prefix foaf may be used as a short hand for the Friend-of-a-Friend vocabulary, which is identified using the IRI http://xmlns.com/foaf/0.1/. A developer may append any of the FOAF vocabulary terms to the end of the prefix to specify a short-hand version of the absolute IRI for the vocabulary term. For example, foaf:name would be expanded to the IRI http://xmlns.com/foaf/0.1/name.