Add RFC8174 to list of normative references and update the use of Requirements Levels

[CDR-API-Stream]

Description

RFC8174 - Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words provides an update to normative reference RFC 2119 - Key words for use in RFCs to Indicate Requirement Levels for Requirement Levels such that requirement levels must be capitalised. This change considers the options for inclusion of RFC8174 as a normative reference and standardisation of requirements level usage in the Data Standards to be capitalised.

Area Affected

Normative References - Requirements Levels and non-capitalised usage of requirement levels.

Change Proposed

A) Update all usage of requirements levels to adopt the capitalised form. B) Update normative references with [RFC8174] in addition to [RFC2119] C) Update the Data Standards introduction with respect to requirements levels as appropriate with reference to [RFC8174]

Optionally: Community feedback has also identified BCP14 - Key words for use in RFCs to Indicate Requirement Levels as an option for best practice usage of requirements levels and usage within the Data Standards. This best practice document communicates the appropriate use of words and capitalisation similar to RFC8174.

Further analysis: Analysis of the update are published here: https://github.com/ConsumerDataStandardsAustralia/standards-maintenance/blob/master/reviews/2021-05/analysis/analysis-rfc2119-rfc8174-20210519.md

[nils-work]

As a starting point, proposing the following changes to be made:

• Replace 'must' with 'MUST' in the following sentence:

  An [RFC4122] UUID used as a correlation id. If provided, the data holder MUST play back this value in the x-fapi-interaction-id response header. If not provided a [RFC4122] UUID value is required to be provided in the response header to track the interaction.

• Replace 'must' with 'MUST' in the following sentence:

  If all versions requested are not supported then the data holder MUST respond with a 406 Not Acceptable.