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OFF-EP 0 — Purpose and Process

Status: Accepted

Authors: Simon Boothroyd

Acceptance criteria: Unanimity

Stakeholders: Karmen Condic-Jurkic, Jeffrey Wagner, David Mobley, John Chodera

Created: 2020-04-01

Discussion: Issue #741

Implementation: openff-standards

What is an OFF-EP?

OFF-EPs (OpenFF Enhancement Proposals) are the mechanism by which the standards employed across the Open Force Field ecosystem are drafted, accepted and updated. OFF-EPs cover both technical and procedural standards, example of which include:

  • the specification of core data models, such the Molecule, Topology and System models.
  • the SMIRNOFF force field specification.
  • the standard operating procedure for curating and adopting data sets, such as the QCA Standards.

Each OFF-EP should clearly and concisely outline what new standard is being introduced or updated, and most importantly, provide a rationale for the change and get input from relevant stakeholders.

Because the OFF-EPs are maintained as text files in a versioned repository, their revision history is the historical record of the standards proposal.


There are three kinds of OFF-EPs:

  1. Standards Track OFF-EPs describe a new feature or implementation
  2. Informational OFF-EPs provide general, non-binding guidance to the community but do not propose a new feature.
  3. Process OFF-EPs describe a change that may not be technical in nature but requires community input.


The OFF-EP process begins with a new idea for Open Force Field infrastructure and/or community. It is highly recommended that a single OFF-EP contain a single key proposal or new idea with a concise scope. Small changes often do not need to go through the OFF-EP process and can be submitted directly to as either a question to the community or a software patch. Each OFF-EP must have a champion -- someone who writes the proposal using the template provded below, shepherds the discussions in the appropriate forums, and attempts to build community consensus around the proposal.


Once a proposal is written, this draft should be submitted as a pull request to the openforcefield/standards repository with the status set to Proposed. It shall be merged at the earliest convenience of maintainers (note that this merge does not imply acceptance, as its status shall still be Proposed). At this point, members of the Open Force Field community will review the submission.

Review and Resolution

All OFF-EPs will be resolved as either Rejected, Accepted or Deferred

An OFF-EP is accepted upon approval by at least three of @SimonBoothroyd, @j-wags, @karmencj, @davidlmobley, and @jchodera.

When an OFF-EP is accepted, it status shall be marked Accepted.

If an OFF-EP is not accepted and the community considers it unlikely to be accepted in the future, it can be rejected and its status shall be marked Rejected. If an OFF-EP is not accepted and the community considers it plausible to be accepted in the future, possibly in a different form, the authors can withdraw it and its status shall be marked Deferred.


OFF-EPs are UTF-8 encoded text files using the Markdown format. A template is provided in the file

This document is based based upon the NEP 0, CFEP 01, and PEP 1

This document is explicitly CC0 1.0 Universal.