Governance · controls in force · method version 0.2

The controls are the product.

Anyone can subtract one published price from another. What an institution buys is the assurance that the same subtraction was done the same way every week, that the inputs were qualified before use, and that a number cannot be quietly changed after the fact. That is what this page documents.

Six controls

Control	What it prevents	Where it is enforced
Input qualification	An unpublished or unsourced number entering the index	src/ingest.mjs — reject on any of six missing fields
Computation separation	A spread being produced by hand and described as derived	src/assess.mjs — the only path to a value
Withholding	A gap being filled by interpolation or a carried price	assess.mjs — returns withheld, never a fallback
Date integrity	Two different days presented as one observation	mixed_dates flag — shown, never smoothed
Append-only issue	A published number being edited in place	src/publish.mjs — refuses to overwrite an existing record
Correction, not revision	History rewritten so the record always looks right	publish.mjs --correct — new dated record with a reason

Each control maps to a file in the repository. This is deliberate: a control that cannot be pointed at is a claim, and claims are what this index exists to avoid.

Integrity of the record

Every publication is written once and hashed. The SHA-256 digest of each record is published on the series page and in the feed, so a reader holding a copy can prove whether it is the copy that was issued.

record issued   →   file written once   →   sha256 computed   →   digest published
                                                       │
                                        a later correction is a new file,
                                        never a new hash on the old one

This is not a distributed ledger and does not claim to be. It is a dated sequence with a verifiable fingerprint, which is what a counterparty actually needs in order to rely on a number in a contract.

Latest attestation

All checks passed · 16/16

run 2026-10-20 17:30Z
1 record · 0 corrections
latest 2026-09-23 · dc56e54727

What was re-derived

Every spread was recomputed from the observations frozen inside its own record, not from today's inputs. Every file was re-hashed. The feed was compared against the record, field by field.

/feed/verification.json

This attestation covers the record published today.

Separation and conflicts

What AVIX does not do

It does not trade SAF, jet fuel or any instrument referencing this index.
It does not advise on, broker or arrange offtakes.
It does not sell recovery, consulting or benchmarking services on top of the assessment.
It does not accept payment contingent on the level of a published spread.

Why that matters

A publisher that earns a fee from the overpayment it reports has an interest in the size of the overpayment. Licensing revenue is flat and unrelated to the direction of any spread. That single design choice removes the largest conflict an index provider can carry.

Where a client also licenses the feed, the licence is priced on distribution, not on the value the client extracts from any individual print.

Errors and complaints

A suspected error in a published spread should be raised at index@xvilan.com with the publication date and the leg in question. The process, in order:

1  acknowledge      within 2 business days
2  verify           against the assessor's own publication, not our file
3  decide           uphold or reject, in writing, with reasons
4  correct          if upheld: new dated correction record, original retained
5  notify           every licensed recipient, on the day the correction issues
6  retain           the complaint, the decision and the correction, indefinitely

There is no fee to complain, and no requirement to be a licensee to raise an error. A reader who finds a mistake is doing the index a service.

Method change control

The method carries a version number, currently 0.2. A change to a spread definition, a unit rule or a qualification test is a new version, published before it takes effect, with the date it applies from. A method change is never applied retrospectively to an issued record.

Where a change would alter a historical spread if recomputed, the series keeps the original and states the break rather than restating history to look continuous.

Regulatory position, stated plainly

AVIX is not an authorised or registered benchmark administrator under Regulation (EU) 2016/1011. It is a publisher of derived spreads. This matters to you if you intend to use a spread in a way the regulation covers:

Reading a spread, or using it for internal analysis and risk work, does not require an authorised administrator.
Referencing a spread in a financial instrument, a fund's objective, or a contract whose value is determined by it can bring the index into scope. In that case the administrator must be authorised, or the use must fall within an applicable exemption.
Any party intending settlement or instrument use is responsible for confirming the position for its own jurisdiction and product, and should not rely on this page as legal advice.

The controls above are built to the standard an authorisation process would examine, because building them later, after a client asks, is not possible. Applying for authorisation is a separate step and is not claimed here.

This paragraph exists because the alternative — saying nothing about regulatory status while publishing something that looks like a benchmark — is how index providers get into trouble. If you need a regulated benchmark, ask, and we will tell you what would have to be true.

Records and retention

Record	Retention	Location
Published publication records	Indefinite, append-only	data/series/
Correction records with reasons	Indefinite	data/corrections/
Input observation sets as ingested	Indefinite, per publication	data/observations.json · embedded in each record
Candidate sets and rejections	Indefinite	data/candidates/
Licence agreements	Term plus six years	Corporate records
Complaints and decisions	Indefinite	Corporate records

Because each publication record embeds the observations it was derived from, the full derivation of any historical spread can be reconstructed from the series alone, without access to any other system.