Glossary
Look up the terms used across the wiki. Follow the linked references for definitions that depend on a particular system or protocol.
Sources and scopeSource record 25 August 2026
Technical source record: 25 August 2026. Check the linked documentation for current product requirements.
Working definitions for this knowledge base; a governing standard or jurisdiction may define a term more narrowly.
On this page
Overview#
The naming conventions explain how this library uses standards titles, requirement words, lifecycle labels, and device neutral terms. This page supplies the compact domain vocabulary.
A to C#
Access control unit (ACU)
A controller that evaluates or enforces access decisions and supervises connected doors, readers, inputs, and outputs. Product architectures vary between intelligent field controllers and host dependent panels.
Actuation
A command or output capable of changing physical state, such as unlocking a door, moving a gate, operating a relay, changing an alarm mode, or controlling equipment. Treat separately from observation.
Adaptive streaming
HTTP delivery in which a manifest describes segmented media representations and a client selects among them. Manifest access, segment authorisation, origin fetching, caching, DRM, and evidence provenance remain separate controls.
Alarm
An asserted condition intended to trigger assessment or response. The system policy and context determine which events become alarms.
Alert lifecycle
The relationship among an original public warning alert and its updates, cancellation, expiry, references, audience, and geographic scope. Receipt isn't proof that a downstream system activated a warning.
Antipassback
Rules intended to prevent credential reuse inconsistent with an entry/exit sequence. Controller partitions, degraded mode, occupancy errors, and emergency policy affect behaviour.
Authority having jurisdiction (AHJ)
The organization or official responsible for interpreting and enforcing applicable codes or requirements. The exact authority depends on location and system.
Attestation
Evidence about an authenticator, device, software, or manufacturing identity evaluated under a stated trust policy. Attestation doesn't identify the current human user or grant an application or physical access permission by itself.
Capability
A supported function with defined limits. Discovery of a capability doesn't prove it is configured, licensed, authorised, safe, or interoperable.
Central station
A monitoring facility that receives alarm communications and performs defined handling procedures. Regulatory and certification meanings are jurisdiction specific.
Codec
An encoder/decoder and its bitstream format, such as H.264, H.265, or Opus. Codec name alone doesn't define profile, level, packetisation, latency, or licensing.
Commissioning
The controlled process of installing, configuring, checking, documenting, and accepting a system against approved requirements.
Conformance
Evidence that an implementation satisfies a named specification, profile, role, and edition under the applicable scheme. It isn't the same as interoperability, secure configuration, or fitness for purpose.
Controller
A component that hosts logic and interfaces to field devices. Always qualify its domain and responsibility rather than relying on the word alone.
Credential
Data or an object used as evidence in an authentication or access process. A credential identifier isn't necessarily a secret, identity, or authorisation decision.
Credit and settlement
Messaging flow control and delivery state concepts used by protocols such as AMQP 1.0. Link credit bounds transfers; settlement resolves messaging responsibility. Neither proves that a business workflow or physical action completed.
D to I#
Degraded mode
An intentional operating state used when a dependency is unavailable. Define allowed functions, cached decisions, time bounds, alerting, reconciliation, and recovery.
Door forced open
A derived condition indicating that the monitored door opened without an expected authorised sequence. Sensor quality, request to exit, timing, and controller logic determine accuracy.
Door held open
A derived condition indicating that a door remained open beyond an allowed interval. It is distinct from forced open and from the raw contact state.
Dry contact
A potential free relay contact used as an electrical state boundary. It carries little semantic information unless supervision, polarity, timing, and ownership are documented.
Edge device
A device near the sensing or actuation boundary, such as a camera, reader peripheral, intercom, gateway, or controller. “Edge” doesn't imply offline autonomy or trustworthiness.
Event
An immutable statement that something was observed or asserted at a time, with source and provenance. Events may be delayed, duplicated, reordered, missing, or corrected.
Fail safe / fail secure
Terms commonly describing a lock's behaviour on loss of power. They don't by themselves determine compliant egress, fire behaviour, emergency release, or whole system failure policy; use qualified design records.
Fabric
In Matter, an administrative trust domain containing operational identities, controllers, nodes, and policy. A device can belong to more than one fabric; commissioning and removal are security lifecycle operations.
Federation
A trust arrangement in which one security domain accepts identity assertions or authentication results from another. Federation doesn't automatically provision accounts, map safe roles, or delegate physical access decisions.
Gateway
A component that mediates between protocols, networks, trust zones, or semantic models. A secure gateway validates, minimises, authorises, rate limits, observes, and fails predictably rather than transparently forwarding everything.
Identity
An entity as represented within a defined authority and lifecycle. Person, credential, account, device, workload, and certificate identities are related but not interchangeable.
Idempotency
A property allowing a repeated operation to have the same intended effect as one application. It must be defined at the business operation level, not inferred solely from an HTTP verb.
Interoperability
The ability of exact implementations to exchange information and produce the intended result under stated conditions. Standards conformance improves the prospects but doesn't guarantee it.
L to R#
Least privilege
Granting only the operations, resources, sites, tenants, and duration required for a role or workload.
Life safety
Functions whose failure may contribute to injury or loss of life, including relevant fire, emergency communication, egress, and safety control functions. Applicability is determined by design and jurisdiction.
Logical node
An IEC 61850 model component that groups standardised data and behaviour for a function. Its name and data objects carry engineering meaning; they aren't interchangeable with raw point addresses.
Manifest
A document describing media presentations, representations, segments, timing, and related metadata in an adaptive streaming system. Treat every URI and declared property as untrusted input.
Mobile credential
A credential presented by a mobile device, commonly using BLE, NFC, or UWB plus a vendor application and cloud/provisioning system. The radio is only one layer of the trust model.
Monitoring
Collection and interpretation of health, state, performance, security, and audit signals. A reachable endpoint isn't proof that the end to end service is healthy.
Normalisation
Mapping source specific observations into a stable internal model while preserving the original meaning, provenance, uncertainty, and raw reference.
Profile
A constrained selection of requirements and options from one or more specifications for a defined role or use case. Name the exact profile and version.
Passage confirmation
Evidence that a person or object traversed a controlled portal in a declared direction. It is distinct from credential authentication, access grant, actuator command, and barrier open state.
Passkey
A discoverable FIDO/WebAuthn credential intended for user authentication, often synchronised or device bound depending on the provider and policy. It isn't a mobile physical access credential merely because both may reside on a phone.
Protocol
A set of rules for communication. A protocol may describe only one layer and may leave data semantics, transport, security, discovery, or lifecycle to other specifications.
Provenance
Information about where data came from and how it was transformed, including source system, device, original identifier, receive time, mapping version, and integrity evidence.
Reader
A credential interaction device. Some readers only forward identifiers; others perform cryptography, biometric processing, PIN entry, mobile communication, or decision support.
Reconciliation
Comparison of event derived or cached state with an authoritative snapshot after gaps, reconnects, restarts, or uncertainty.
Restore
An event indicating that a previously asserted condition is no longer asserted. It doesn't necessarily mean an incident was resolved, acknowledged, or closed.
S to Z#
Secure mode
A protocol or product specific protected mode. The phrase is incomplete without authentication, encryption, key lifecycle, downgrade behaviour, and exact configuration.
Security vestibule
An access controlled passage space using two or more coordinated doors or barriers. Use this neutral term in new material; “mantrap” remains a legacy search term. Egress, entrapment, accessibility, occupancy sensing, and emergency release need qualified design.
Security Configuration Language (SCL)
The IEC 61850 engineering representation for system, device, communication, and data model configuration. SCL files are sensitive, versioned inputs whose integrity and deployment state require change control.
Sensor
A component that observes a physical or environmental condition. Its output may be raw, filtered, inferred, stale, tampered with, or unavailable.
State
A condition believed to hold over an interval, usually reconstructed from snapshots and events. Include freshness, confidence, and source.
Supervision
Mechanisms intended to detect faults, substitution, communication loss, wiring conditions, or missed check ins. Exact detection and timing depend on the interface and configuration.
System of record
The authority designated to own a class of data or decisions. There may be different systems of record for identity, credentials, access rules, video retention, incidents, and assets.
Tailgating
Passage by an additional person or object through a controlled boundary without the intended independent authorisation. Detection and prevention technologies have privacy, accuracy, and safety implications.
Tenant
An administrative security boundary in a shared service. Every identity, resource, event, query, token, and audit record should carry and enforce tenant scope where multi tenancy exists.
Trust boundary
A boundary across which identity, authority, data quality, ownership, or consequence assumptions change. Validate and authorise at the boundary.
Unknown / indeterminate
An explicit state used when the system lacks sufficient trustworthy evidence. It is safer than guessing false, closed, healthy, or denied.
Verification
Evidence that a statement, document, design, or implementation meets its stated review level. In this library, V3 requires a linked record for an exact claim and environment.
WebAuthn ceremony
The challenge/response sequence by which a relying party registers or authenticates a public key credential through a browser/client and authenticator. Origin, relying party ID, challenge, user verification, credential policy, and server side validation all matter.
Video management system (VMS)
A system that manages cameras, live/recorded media, users, events, exports, health, and related integrations. Product and deployment boundaries vary.
Zone
A named grouping used for alarm, access, detection, or network policy. Always qualify the owning system; similarly named zones need not share semantics.