---
title: "ETSI TS 103 280: the common-parameter dictionary"
chapter: "12"
---

# ETSI TS 103 280: the common-parameter dictionary

TS 103 280 centralizes common LI and disclosure parameters used across ETSI TC LI specifications. A shared dictionary reduces contradictory definitions, but only when every interface pins compatible editions and national extensions.

> **Safety boundary:** this chapter teaches lawful, governed system design from
> public standards. It does not provide operational targeting, activation,
> decryption, surveillance-evasion, or covert collection instructions.

## The mental model

| Concept | Plain meaning | Control that must travel with it |
|---|---|---|
| **Common dictionary** | One authoritative definition for reused parameters | Names alone do not ensure semantic agreement |
| **Version alignment** | Interfaces agree which dictionary edition applies | Independent upgrades can break decoding |
| **Enumerations** | Controlled values prevent free-text ambiguity | Unknown values need safe behavior |
| **Identifiers** | Consistent cases, parties, endpoints, and locations can correlate | Minimize and classify identifiers |
| **Time representation** | Events can be compared across systems | Clock source, zone, precision, and uncertainty matter |
| **National extension** | Approved jurisdiction-specific additions | Extension namespaces and ownership must be governed |

## Apply it as a controlled workflow

1. Create a dependency graph from each interface standard to TS 103 280.
2. Pin dictionary versions in build, schema registry, and conformance fixtures.
3. Define safe handling for unknown optional and mandatory values.
4. Normalize time and identity only through reviewed mappings.
5. Track national extensions as controlled products.
6. Regression-test producers and receivers before rollout.

## Evidence to demand

- Schema compatibility checks run in CI and bilateral qualification.
- Time synchronization quality and drift are monitored without payload.
- Identifier formats are validated but never used as sole legal authority.
- Extension ownership, documentation, and expiry are visible.

## Failure to reason about

A location field changes precision in a dictionary update. The wire still parses, but policy decisions and downstream interpretation differ. Semantic compatibility tests must go beyond successful decoding.

## Feynman check

TS 103 280 is the shared dictionary. If two systems use different editions, the same word may no longer mean exactly the same thing.