OOF™ Origin Open Foundation™

Independent Methodological Authority

Architecture Ecosystem: Structured Reality Standards™
Architecture Family: TREGA™ — Tax-Relevant Event Governance Architecture™
Parent Standard: TREPS — Tax-Relevant Event Participation Standard
Module: EPIM — Event Participant Identification Module
Operational Layer: Event Participant Identification Governance Layer
Category: Governance & Enforcement
Subcategory: Tax-Relevant Event Governance
Type: Core Module
Governed Space: Event Participant Identification
Origin ID: TREGA-TREPS-EPIM-001
Version: 1.0
Status: Canonical · Open Standard
Effective Date: 1 September 2026
AI-Readable: Yes
Authority: OOF®
Protection: MIP® — Methodology Intellectual Property Protection
Canonical Language: UCL — Universal Canonical Language

Canonical Definition

The Event Participant Identification Module (EPIM) governs how
actors potentially relevant to a Tax-Relevant Event are
identified, distinguished, referenced, and maintained as stable
Participant Candidates for subsequent participation governance.

EPIM establishes whether available actor information is
sufficient to distinguish one actor from another within the
context of the governed event.

Its purpose is not to determine whether an identified actor
materially participated in the event.

Its purpose is to establish which actor is under participation
governance.

The principal distinction is: Identified
Actor ≠ Governed Event Participant

An actor may be identifiable without materially participating in
the event.

Participation role, actor-event association, machine and
autonomous participation, and participation continuity are
governed by subsequent TREPS modules.

Operational Role

Modern operational events may contain references to many actors.

These may include humans, organizations, platforms, software
systems, machines, AI agents, autonomous systems, infrastructure
providers, intermediaries, accounts, devices, or other
operational entities.

The same actor may also appear differently across multiple
systems.

A company name may vary.

A person may appear through different account identifiers.

A machine may be represented through a device ID, asset record,
serial number, or system identifier.

An AI agent may operate through multiple sessions or technical
instances.

A platform may appear through several legal, commercial, or
technical references.

EPIM establishes sufficient actor differentiation so that
subsequent TREPS governance does not confuse different actors or
incorrectly treat multiple references to the same actor as
multiple participants.

Internal Module Flow

TREPS is operationalized through the following internal flow:

EPIM — Participant Identification

→ EPRM — Participation Role

→ EPAM — Actor Association

→ EPMAM — Machine & Autonomous Actor Governance

→ EPCM — Participation Continuity

→ Governed Participatory Event

EPIM is the first module.

It establishes the actor reference upon which subsequent
participation governance can operate.

Operational Transition

EPIM receives actor-related information associated with the:

Governed Temporally and Spatially Situated
Event

and produces: Governed Participant Candidate Set

The canonical transition is:

Actor Information Associated with the
Governed Event

↓

EPIM

↓

Governed Participant Candidate Set

A Participant Candidate is an actor sufficiently identified for
participation governance.

It is not yet a confirmed Governed Event Participant.

Operational Space

EPIM governs participant-identification operations including:
actor discovery; actor differentiation; actor reference
establishment; duplicate actor detection; ambiguous actor
handling; conflicting actor identification; human actor
references; organizational actor references; digital actor
references; machine actor references; autonomous actor
references; cross-system actor references; identification
confidence; identification traceability; and
participant-candidate formation.

EPIM governs these mechanisms only to the extent necessary to
establish stable actor references for TREPS.

It does not replace comprehensive identity governance.

Operational Scope

EPIM may operate across events involving: individuals; companies;
institutions; marketplaces; platforms; software services;
accounts; AI agents; autonomous systems; robots; machines;
devices; infrastructure systems; machine-to-machine environments;
and other distinguishable operational actors.

EPIM remains neutral to whether an actor is human,
organizational, digital, or autonomous.

Actor Identification

EPIM shall establish whether an actor can be sufficiently
distinguished from other actors relevant to participation
governance.

Identification may rely on one or more available references.

These may include, where appropriate: governed identity
references; organizational identifiers; account identifiers;
platform identifiers; system identifiers; machine identifiers;
device identifiers; transaction-associated actor references;
operational records; external governed references; or
combinations of relevant identification information.

No single identifier type is universally authoritative.

Identifier Availability ≠ Actor Identification Sufficiency.

Identification must be adequate for the operational purpose of
TREPS.

Participant Candidate

Where an actor is sufficiently distinguishable for subsequent
participation governance, EPIM may establish that actor as a:
Participant Candidate

Participant Candidate means:

an identified actor whose possible participation in the governed
event requires subsequent TREPS governance.

This state deliberately precedes confirmed Event Participation.

Therefore:

Participant Candidate ≠ Governed Event
Participant

EPRM and EPAM subsequently determine the relevant participation
structure.

Actor Reference Stability

A governed participant candidate requires a sufficiently stable
reference.

The reference must allow subsequent TREPS modules to determine
that they are operating on the same actor.

A stable reference does not require every underlying source
system to use the same identifier.

Instead, EPIM shall preserve sufficient linkage to distinguish:

Same Actor / Multiple References

from:

Different Actors / Similar References

This prevents fragmented source data from unnecessarily
fragmenting the participation structure.

Multiple References to the Same Actor

One actor may appear through multiple records.

For example:

Company Name + Platform Account + Merchant
ID + Payment Account

may represent the same underlying organization.

Likewise:

Machine Serial Number + Asset ID + Device
ID + Network Identifier

may refer to the same machine.

EPIM shall permit multiple references to be associated with one
Participant Candidate where sufficient governance supports that
association.

However:

Multiple Actor References ≠ Multiple Actors by Default.

Similar References to Different Actors

The opposite problem must also be governed.

Different actors may share: similar names; shared addresses;
shared infrastructure; group-level identifiers; platform
accounts; devices; corporate branding; or organizational
relationships.

EPIM shall not merge actors merely because available records
appear similar.

Reference Similarity ≠ Actor Equivalence.

Human Actor Identification

Where the potential participant is human, EPIM shall establish
only the degree of identification required for participation
governance.

EPIM shall not unnecessarily reconstruct or govern the person's
complete identity.

Where authoritative identity governance is required, governed
identity information may be consumed from OBIDENITY® or another
legitimate identity source.

Participant Identification ≠ Complete Human Identity Governance.

Organizational Actor Identification

Organizations may appear under: legal names; trading names;
subsidiaries; branches; business units; platform accounts; group
structures; or technical system references.

EPIM shall distinguish the actor actually under participation
governance from related organizations where available evidence
permits.

Corporate Relationship ≠ Actor Equivalence.

A parent company, subsidiary, branch, platform operator, and
merchant shall not automatically be treated as the same actor.

Digital Actor Identification

Digital environments may contain actors represented primarily
through technical references.

EPIM shall permit digital actors to be identified where they can
be sufficiently distinguished for participation governance.

A technical identifier may support identification without
establishing participation.

Therefore:

Digital Identifier ≠ Event Participation.

Machine and Autonomous Actor
Identification

Machines, robots, AI agents, and autonomous systems may require
identification independently from their owners, developers,
operators, or supervising organizations.

EPIM shall support such actors as distinct Participant Candidates
where operational reality requires it.

Therefore:

Machine Identity Reference ≠ Owner Identity.

AI Agent Reference ≠ Developer Identity.

Autonomous System Reference ≠ Human Operator Identity.

Whether these actors materially participate is governed
subsequently within TREPS.

Identification Source Governance

Actor identification may originate from multiple sources.

EPIM shall preserve the distinction between the actor and the
source describing the actor.

Identification Source ≠ Identified Actor.

A source may be incomplete, outdated, ambiguous, conflicting, or
technically generated.

EPIM shall therefore preserve sufficient source traceability to
support later review.

Identification Confidence

Not every actor can be identified with equal certainty.

EPIM shall allow identification confidence to be qualified where
required.

Possible conditions may include:

Established

Qualified

Ambiguous

Conflicted

Unresolved

An actor shall not be assigned artificial certainty merely
because downstream systems require a participant field.

Required Participant Field ≠ Permission to Invent Actor
Certainty.

Ambiguous Actor Identification

Where available information may correspond to more than one
actor, EPIM shall preserve that ambiguity until sufficient
information supports differentiation.

Ambiguity shall not be resolved through convenience alone.

Actor Ambiguity ≠ Permission for Arbitrary Actor Selection.

Conflicting Actor Identification

Different sources may provide materially incompatible
identification information.

EPIM shall preserve material conflicts and prevent silent
replacement of one actor reference by another.

Where conflict cannot legitimately be resolved, the Participant
Candidate may remain qualified or unresolved.

Identification Conflict ≠ Permission for Convenient Identity
Selection.

Duplicate Identification

EPIM shall reduce the risk that the same actor becomes
represented as several independent Participant Candidates merely
because different systems use different identifiers.

Duplicate resolution shall remain traceable.

The objective is:

One Governed Actor Reference where evidence supports one actor.

However, consolidation shall not occur where actor equivalence
remains materially uncertain.

Identification Change

Actor information may change while the governed event remains the
same.

Examples include changes to: names; account identifiers; system
references; organizational labels; machine identifiers; or
platform representations.

EPIM shall preserve materially relevant identification changes
without automatically creating a new actor.

Identification Change ≠ New Actor by Default.

Historical references required for traceability shall remain
reconstructable.

Cross-System Identification

The same actor may appear across ERP, commerce, banking,
logistics, platform, machine, or autonomous-system records.

EPIM shall support governed linkage across these systems where
sufficient evidence establishes that the references concern the
same actor.

Cross-system linkage must remain traceable.

Cross-System Match ≠ Actor Equivalence Without Sufficient
Support.

Relationship to OBIDENITY®

EPIM does not own comprehensive identity governance.

OBIDENITY® governs origin-bound identity structures including
identity, origin, ownership, authority, permission, provenance,
transfer, continuity, and auditability where applicable.

EPIM consumes only the actor-identification information necessary
for Event Participation governance.

The boundary is:

OBIDENITY® governs who the actor is as a governed identity.

EPIM governs whether that actor can be sufficiently distinguished
as a Participant Candidate within the TREPS process.

Therefore:

Actor Identity ≠ Participant
Identification

and:

Participant Identification ≠ Event
Participation Relationship to Event
Location

An actor may be identified through location-associated records.

Location alone does not establish actor identity or
participation.

Therefore:

Location Reference ≠ Actor Identification by Default.

Actor Location ≠ Event Participation.

TRELS remains authoritative for Event Location.

Relationship to Participation Role

EPIM does not determine what operational role an identified actor
performs.

That belongs to:

EPRM — Event Participation Role Module

Therefore:

Participant Identification ≠ Participation Role.

EPIM answers:

Which actor is under participation governance?

EPRM answers:

What operational participation role does that actor perform?
Relationship to Actor–Event Association

EPIM does not establish that a Participant Candidate materially
participates in the governed event.

That relationship is governed subsequently through EPAM.

Therefore:

Identified Actor ≠ Actor–Event Association

and:

Participant Candidate ≠ Governed Event Participant.

This separation prevents the existence of an actor in a record
from becoming automatic proof of participation.

Governance States

EPIM may assign identification states including:

Actor Reference Detected

Identification Under Governance

Actor Distinguished

Actor Qualified

Actor Ambiguous

Actor Conflicted

Actor Unresolved

Participant Candidate Established

These states describe identification governance only.

They do not establish Event Participation.

Governance Requirements

EPIM implementations shall ensure that: actor references relevant
to participation governance can be identified; materially
different actors remain distinguishable; multiple references to
the same actor can be governed; similar references are not
automatically merged; human, organizational, digital, machine,
and autonomous actors can be represented; identification sources
remain traceable; identification uncertainty remains visible;
material identification conflicts remain visible; duplicate actor
representations can be governed; identification changes remain
traceable; cross-system references can be linked where
sufficiently supported; complete identity governance is not
duplicated; participation roles are not prematurely assigned;
actor-event participation is not prematurely established; and
taxpayer or other legal status is not inferred from
identification.

Governance Logic

IF actor-related information is materially relevant to
participation governance, THEN EPIM shall evaluate whether the
actor can be sufficiently distinguished.

IF sufficient identification exists, THEN a stable Participant
Candidate reference may be established.

IF multiple references sufficiently correspond to the same actor,
THEN they may be governed under one Participant Candidate while
preserving source traceability.

IF actor equivalence remains uncertain, THEN separate or
qualified references shall be preserved.

IF identification is ambiguous or conflicted, THEN uncertainty
shall remain visible.

IF a Participant Candidate is established, THEN the actor may
proceed to subsequent TREPS governance.

EPIM SHALL NOT treat identification alone as proof of Event
Participation.

Minimum Implementation Framework

A minimum EPIM implementation should support:

Governed Event Reference

The event within which participant identification is being
performed.

Participant Candidate Identifier

The stable reference created for the identified actor.

Actor Type

The governed actor category relevant to participation processing.

Source Actor Reference

The original actor reference supplied by a source system or
governed source.

Identification Source

The source from which identification information originates.

Reference Linkage

The relationship between multiple references believed to concern
the same actor.

Differentiation State

Whether the actor is sufficiently distinguishable from other
actors.

Duplicate State

Whether multiple references may represent the same actor.

Identification Confidence

The qualified confidence attached to the identification.

Ambiguity State

Whether actor identity remains materially ambiguous.

Conflict State

Whether identification sources materially conflict.

Traceability Reference

The information required to reconstruct the identification
decision.

Governance State

The current EPIM identification state.

Handoff State

Whether the Participant Candidate is sufficiently governed to
proceed to EPRM.

Governance Outputs

EPIM may produce: Governed Actor Reference; Participant Candidate
Identifier; Actor Type Representation; Actor Reference Linkage;
Duplicate Actor Resolution; Identification Confidence State;
Actor Ambiguity State; Actor Conflict State; Identification
Traceability Record; Participant Candidate Governance State; and
the principal output:

Governed Participant Candidate Set

The output represents actors sufficiently identified for
subsequent participation governance.

It does not represent confirmed Event Participants.

Critical Distinctions

Identified Actor ≠ Governed Event
Participant

Participant Candidate ≠ Governed Event
Participant

Participant Identification ≠ Event
Participation

Actor Identity ≠ Participant
Identification

Participant Identification ≠ Complete
Identity Governance

Identifier Availability ≠ Actor
Identification Sufficiency

Multiple Actor References ≠ Multiple
Actors by Default

Reference Similarity ≠ Actor Equivalence

Corporate Relationship ≠ Actor Equivalence

Digital Identifier ≠ Event Participation

Machine Identity Reference ≠ Owner
Identity

AI Agent Reference ≠ Developer Identity

Autonomous System Reference ≠ Human
Operator Identity

Identification Source ≠ Identified Actor

Required Participant Field ≠ Permission to
Invent Actor Certainty

Actor Ambiguity ≠ Permission for Arbitrary
Actor Selection

Identification Change ≠ New Actor by
Default

Participant Identification ≠ Participation
Role

Identified Actor ≠ Actor–Event Association

Participant Identification ≠ Taxpayer
Identification Enterprise Application

EPIM can operate between operational systems and the remaining
TREPS participation-governance process:

ERP / Commerce / Banking / Platform / AI
Agent / Machine System

→ Actor-Related Event Information

→ EPIM

→ Governed Participant Candidate Set

→ EPRM — Participation Role Governance

→ Remaining TREPS Modules

→ Governed Participatory Event

This provides downstream systems with stable actor references
without prematurely assigning participation, legal identity, or
tax status. Use Case 1 — Multi-Platform Commercial Event

A commercial event contains a merchant name, marketplace seller
ID, payment-account reference, logistics customer number, and
corporate identifier.

Several references may describe the same organization, while
another similarly named company belongs to the same corporate
group.

EPIM governs the references, distinguishes the relevant actors,
prevents unsupported merging, and establishes a stable
Participant Candidate for subsequent participation governance.

It does not yet determine whether the merchant, marketplace,
payment provider, or logistics provider materially participated
in the event or what legal tax status any actor possesses. Use
Case 2 — Autonomous Industrial Event

An autonomous production event contains references to an
industrial robot, machine controller, AI optimization agent,
equipment owner, software provider, operating company, and remote
monitoring system.

EPIM distinguishes the machine and autonomous actors from the
organizations and humans associated with them and establishes
stable Participant Candidates where sufficient identification
exists.

It does not assume that the machine owner is the machine
participant, that the AI developer is the AI participant, or that
every identifiable actor materially participated in the event.

Those questions proceed through subsequent TREPS governance.

Canonical Boundary

EPIM owns the identification, differentiation, stable
referencing, duplicate governance, ambiguity governance, conflict
preservation, cross-system linkage, and identification
traceability required to establish Participant Candidates for
TREPS.

EPIM does not own complete identity, origin, ownership,
authority, permission, or provenance governance.

It does not determine Participation Role, final Actor–Event
Association, machine/autonomous participation status,
Participation Continuity, Event Location, Value Association,
accountability, responsibility, liability, taxpayer status, Tax
Jurisdiction, tax nexus, permanent establishment, legal
taxability, Tax Liability, or another jurisdiction-specific legal
conclusion.

Its governance ends when actors are sufficiently identified and
represented as Participant Candidates for subsequent TREPS
processing.

Canonical Handoff

Governed Temporally and Spatially Situated
Event + Actor Information

→ EPIM — Governed Participant Candidate Set

→ EPRM — Event Participation Role Governance

Canonical Closing Statement

EPIM establishes which actor is sufficiently identifiable to
enter participation governance without treating identification
itself as proof of participation.

Knowing who an actor is does not establish whether or how that
actor participated in the event.

Identified Actor ≠ Governed Event Participant.