Sync this repo against virtru/tdf-spec@aaeb3f9 (#3)

- Made minor edits to switch the OpenTDF nonclamenture where appropriate

.github/PULL_REQUEST_TEMPLATE.md

@@ -5,12 +5,13 @@
 ### Checklist
 
 - [ ] A clear description of the change has been included in this PR.
-- [ ] Spec Semver version has been updated in the VERSION file
-- [ ] Tagged this branch with new semver version and an annotation describing the change (ex: `git tag -s 4.1.0 -m "Spec version 4.1.0 - did a thing"`)
+- [ ] A clear description of whether this change is a _Major_, _Minor_, _Patch_ or _cosmetic_ change as per the [Versioning Guidelines](../CONTRIBUTING.md#version-changes) has been included in this PR.
 - [ ] All schema validation tests have been updated appropriately and are passing.
-- [ ] Version numbers have been updated as per the [Versioning Guidelines](../CONTRIBUTING.md#verison-changes).
-- [ ] Major/minor version changes only: A writeup has been included discussing the motivation and impact of this change.
-- [ ] Major/minor version changes only: The minimum wait time has elapsed.
-- [ ] Project version changes only: I have updated both the `VERSION` file and the `git tag`.
+- [ ] MAJOR/MINOR VERSION CHANGES ONLY: This PR should be made in branches prefixed with `draft-<change>`
+- [ ] MAJOR/MINOR VERSION CHANGES ONLY: A link to a reference implementation (PR or set of PRs) of the change has been included in this PR.
+- [ ] MAJOR/MINOR VERSION CHANGES ONLY: A writeup has been included discussing the motivation and impact of this change.
+- [ ] MAJOR/MINOR VERSION CHANGES ONLY: The minimum wait time has elapsed.
+- [ ] DRAFT MERGE ONLY: Draft Semver has been updated in the VERSION file (optional)
+- [ ] DRAFT MERGE ONLY: Tagged this branch with new semver version and an annotation describing the change (ex: `git tag -s 4.1.0 -m "Spec version 4.1.0 - did a thing"`)
+- [ ] DRAFT MERGE ONLY: Version numbers have been updated as per the [Versioning Guidelines](../CONTRIBUTING.md#version-changes).
 - [ ] This change otherwise adheres to the project [Contribution Guidelines](../CONTRIBUTING.md).
-- [ ] Every item in this checklist has been completed.

CONTRIBUTING.md

@@ -1,22 +1,25 @@
 # Contribution guidelines
 
-Contributions to the TDF3 specification are welcome! Please be sure to follow these guidelines when proposing changes or submitting feedback.
+Contributions to the TDF specification are welcome! Please be sure to follow these guidelines when proposing changes or submitting feedback.
 
 ## Proposing Changes
 
-All changes must be proposed using a pull request against this repo. See the GitHub [howto](https://help.github.com/en/articles/about-pull-requests) for more information about publishing a PR from a fork. The PR template checklist must be satisfied before review can take place (with the exception of blocking items like wait time).
+1. Pull Requests(PRs) proposing changes should be made in branches prefixed with `draft-<change>`
+2. If the changes proposed to the spec would result in a _Major_ or _Minor_ semver version bump (see [versioning guidelines](#version-changes)) to the spec, the spec change MUST LINK TO A REFERENCE IMPLEMENTATION OF THE CHANGES in a publicly-visible Git repository.
+ - It is suggested that the PR include a link to one or more reference implementation PRs in [the openTDF project's reference implementation](https://github.com/opentdf)
 
-Changes must update version numbers as required (see [guidelines](#version-changes)). 
+Proposed changes must specify what kind of semver change they would cause - (see [guidelines](#version-changes)).
 
 * _Major_ version changes must include a detailed writeup motivating the change and its impact. These PRs must be left open for review for at least 7 days.
 * _Minor_ version changes must include a brief writeup motivating the change and its impact. These PRs must be left open for review for at least 3 days.
+* _Patch_ version changes must include a brief writeup motivating the change and its impact. These PRs must be left open for review for at least 3 days.
 
 ### Version Changes
 
 We follow the [semver](https://semver.org/spec/v2.0.0.html) guidelines on version changes, although reviewers may exercise their discretion on individual PRs.
 
-* _Major_ version revs when a backwards-incompatible change is made. (Example: new required manifest fields or new required API call.)
-* _Minor_ version revs when backwards-compatible functionality is added. (Example: new optional API parameter.)
+* _Major_ version revs when a backwards-incompatible change is made that would break clients. (Example: new required manifest fields or new required API call, or client code changes required)
+* _Minor_ version revs when backwards-compatible functionality is added that would not break clients. (Example: new optional API parameter.)
 * _Patch_ version revs when a change does not affect functionality but could affect how readers interpret the spec. (Example: Substantive new diagram illustrating a previously poorly-documented protocol interaction.)
 * Cosmetic changes should _not_ affect the version number. (Example: Fixing typos, reformatting docs.)