Structural Lexicon

Custody Event

Any event that requires interaction with the custody setup — a transfer, a recovery attempt, a key rotation, an inheritance claim, or a verification check. Custody events test whether the setup works under the conditions the event creates.

See Custody Learning Path, Custody Certification.

Custody Behavior

How a custody setup actually performs under specific conditions, as distinct from how it was designed to perform. Custody behavior may differ from the original design because of time, human error, or technical changes.

See Hot-Cold Allocation, Cognitive Decline.

Stress Surface

A condition or scenario that applies pressure to a custody setup, showing whether it holds together or breaks down. Stress surfaces include time, absence of key people, outdated devices, legal events, emotional distress, and coordination demands.

See Custody Certification.

Failure Surface

A specific point in a custody setup where loss, delay, or access denial may occur. Every custody setup has failure surfaces. The stress test identifies where they are and what activates them.

See After Moving to Cold Storage, Address Verification.

Custody Stress Test

A structured look at what happens when stress is applied to a custody system. The stress test does not say whether a setup is good or bad. It documents the conditions, the dependencies, and where the setup may behave differently than the holder expects.

Referenced across all memos.

Survivability

Whether a custody setup continues to work — preserving access and preventing loss — after a specific stress event. Survivability is assessed by scenario. A setup may survive the holder's incapacity but not a key compromise, or survive a device failure but not a coordination breakdown.

Referenced across all memos.

Silent Invalidity

A condition where a custody setup has stopped working as intended but nothing signals the problem. A backup may be corrupted. A passphrase may be forgotten. Firmware may be outdated. A cosigner may be unreachable. Nothing alerts anyone until access is needed.

See Custody Looks Valid Isn't.

Illusory Redundancy

A condition where multiple backups or copies appear to provide safety but share a common risk that can disable all of them at once. Three copies of a seed phrase in the same building do not create true redundancy. Two wallets created from the same seed share the same risk.

See Backup Path Testing.

Entropy

The tendency of custody setups to degrade over time through changes in environment, memory, technology, and relationships. Entropy is not a single failure. It is the slow process that creates distance between how a setup was designed and how it works today.

See Custody Entropy, Custody Degrades Over Time.

Degradation

A measurable reduction in how well a custody setup works. Degradation may be gradual (firmware aging, memory decay, relationship drift) or sudden (device failure, key compromise, death). Degradation is the visible effect. Entropy is the underlying process.

See Custody Degrades Over Time, Backup Path Testing.

Single Point of Failure

A component whose failure alone causes loss or permanent access denial. A single private key, a single device, a single person who holds all credentials, or a single location where all backup materials are stored.

See Backup Spouse Can Use, Self-Custody Risks.

Knowledge Concentration

A condition where critical custody information — passwords, seed phrase locations, device procedures — exists only in one person's memory or in documentation accessible only to that person. Knowledge concentration is one of the most common risks in self-custody.

See Custody Retirement, Duress Wallet Inheritance.

Coordination Friction

The difficulty or delay that occurs when multiple people must act together to complete a custody task. They may not share location, availability, technical skill, or willingness to cooperate. Multisig setups, shared custody, and inheritance involving multiple heirs all introduce coordination friction.

See Exchange Bankruptcy Inheritance.

Access Path

A sequence of steps, credentials, devices, and knowledge required to move bitcoin from a specific custody setup. An access path may be direct (holder uses their own device and key) or indirect (executor follows documented instructions using backup materials). Each access path has its own failure surfaces.

See After Moving to Cold Storage, Audit My Wallet.

Activation Gap

The period between when legal authority is granted (through a power of attorney, court order, or estate document) and when technical access is actually achieved. During the activation gap, the bitcoin is legally assigned but cannot be moved. Custody events may occur during this period, but the authorized person may not be able to act.

See Durable POA Timing, Springing POA Problem.

Credential Separation

Distributing custody credentials across different locations, media, or individuals so that no single point of compromise grants full access. Credential separation increases security but makes recovery and coordination more complex.

See Backup Path Testing.

Authority-Access Gap

The structural condition where legal authority over bitcoin (granted by a court, estate document, or power of attorney) does not produce technical access to the bitcoin. The legal system assigns ownership; the Bitcoin network assigns control through cryptographic keys. These systems do not communicate.

See Authority-Access Gap.

Operational Reality

The actual state of a custody arrangement as it exists in practice, not as described on paper. Operational reality includes the actual devices, backup locations, firmware versions, and the real technical ability of the people involved.

See Advisor Custody Risk Assessment, Custody Selection.

Institutional Intermediation

The presence of a third-party institution (bank, brokerage, exchange, custodian) between legal authority and asset access. Traditional assets rely on institutions to convert legal documents into asset transfers. Self-custody bitcoin has no intermediary. Legal authority alone does not produce access.

See Authority-Access Gap.

Legal Authority

The right to control, transfer, or manage bitcoin as recognized by the legal system — through estate documents, court orders, powers of attorney, or trust instruments. Legal authority is necessary but not sufficient for bitcoin access in self-custody.

See Fiduciary Duty, Executor Authority vs Signer.

Modeled Behavior

A description of how a custody arrangement is expected to perform under a specific scenario, based on the setup's characteristics rather than watching that exact scenario happen. The stress test produces modeled behavior, not prediction.

See Cognitive Decline, Heirs Can Use.

Observed Pattern

A recurring feature found across many custody setups. Observed patterns describe how setups commonly behave, not how any single setup will behave. Patterns are identified through structural analysis, not through statistical data collection.

See Hot-Cold Allocation.

Coverage Boundary

The limit of what a custody product, service, or professional engagement addresses. Conditions outside the coverage boundary are not examined or protected by that instrument. The stress test documents where coverage boundaries exist and what falls outside them.

See Custody Certification.

Composure

The emotional and cognitive state of the person trying to use a custody setup. Setups designed during calm conditions may be operated during grief, panic, time pressure, or cognitive decline. The difference between setup conditions and execution conditions is a stress variable.

See Cognitive Decline.

Grief

An emotional state present in nearly all inheritance scenarios that affects the heir's or executor's ability to follow technical custody procedures accurately. Multi-step custody procedures may fail when the operator is grieving.

See Heirs Can Use.

Cognitive Decline

A gradual reduction in the holder's ability to manage their custody setup — through aging, dementia, or neurological conditions. Unlike sudden incapacity, cognitive decline is gradual. The holder may still function but begin making errors or forgetting steps without noticing the change.

See Cognitive Decline.

Descriptive Only

The editorial posture of all reference memos in this library. Materials describe observed conditions, patterns, and dependencies. They do not prescribe actions, recommend practices, or set standards.

Referenced across all memos.

Non-Advisory

The classification of all outputs produced by CustodyStress. The instrument does not provide investment advice, legal advice, custody recommendations, or product endorsements. Use of the instrument does not create a professional relationship.

See Terms, Legal.