# SQLBL 1019:2026 — Signal Fidelity Terminology — Controlled Descriptor for Communication Quality

URL: https://sqlbl.com/standards/sqlbl-1019
Status: Published | Edition: 2 | Published: 2026-05-13
Committee: SQLBL/TC 19 Measurement and Conformance | Category: Measurement & Conformance | Pages: 28
Keywords: signal, fidelity, terminology, controlled, descriptor

## Abstract

Introduces a controlled descriptor for communication quality expressed as the ratio of received to intended meaning, together with a permitted usage envelope.

## 1 Scope

This document specifies requirements for signal fidelity terminology in professional and quasi-professional written communication.
It applies to assessments of communication quality in professional and organizational settings.
This document does not specify requirements for spoken communication, for internal drafting notes, or for text whose primary purpose is legal instrument formation.

## 2 Normative references

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document.
- SQLBL 1000, Structured language — Vocabulary and verbal forms
For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document applies.

## 3 Terms and definitions

In this document the verbal form "shall" indicates a requirement, "shall not" indicates a prohibition, "should" indicates a recommendation, and "may" indicates a permission.
Terms and definitions given in SQLBL 1000 and the following apply.
**3.1 signal fidelity** — degree to which the meaning reconstructed by the receiver matches the meaning intended by the sender
**3.2 degradation event** — identifiable point at which fidelity is lost

## 4 General principles

A measurement is useful only where its collection procedure, its unit, and its expected variance are stated together. This document requires all three.
Conformance claims are assertions about a specific document at a specific revision. They are not assertions about an author, an organization, or a process.
Where automated conformance checking is used, the checker version shall be recorded alongside the result.

## 5 Requirements

5.1 Communication quality may be described as "signal fidelity".
5.2 Where the descriptor is used, at least one degradation event shall be identified.
5.3 The descriptor shall not be used as a synonym for volume, frequency, or responsiveness.
5.4 Numerical fidelity claims shall state the measurement procedure.

## 6 Conformance

A document conforms to SQLBL 1019:2026 where every requirement expressed with the verbal form "shall" in Clause 5 is satisfied and no requirement expressed as "shall not" is violated.
Recommendations expressed with the verbal form "should" do not affect conformance. Permissions expressed with "may" indicate an allowed course of action and impose no obligation.
Conformance claims shall take the form: "This document conforms to SQLBL 1019:2026, Edition 1." Partial conformance shall be declared by clause number, for example "conforms to SQLBL 1019:2026 Clauses 5.1 and 5.2 only."
Conformance may be assessed manually or by an automated checker. Where an automated checker is used, the assessment record shall identify the checker and the catalog release of SQLBL-1019 against which it was run.

## 7 Implementation guidance

The descriptor is permissive rather than mandatory; it is intended for use where the failure being described is interpretive rather than logistical.
Assessors should reject uses in which no degradation event can be named.
Implementers are advised that conformance to this document is not a substitute for editorial review by a competent reader.

## 8 Examples

**EXAMPLE 1 — Conforming.** Signal fidelity dropped at the handoff between design review and implementation, where the constraint list was summarised rather than transferred.
**EXAMPLE 1 — Non-conforming.** Communication was strong throughout and everyone stayed aligned.

## Annex A Annex A (informative) — Assessment checklist

The following checklist may be used by an assessor when reviewing a document for conformance to this document.
- Degradation event identified.
- No synonym drift.
- Measurement procedure stated for numeric claims.
- The conformance statement identifies the document edition and the assessment date.
- Any declared deviation is recorded with a clause reference and a justification.

## Bibliography Bibliography

- SQLBL 1000, Structured language — Vocabulary and verbal forms
- SQLBL 9001, Corpus construction — Principles and traceability
- SQLBL 9004, Conformance assessment — Guidance for assessors
- SQLBL/TR 929, Technical report on observed usage in measurement & conformance

## Normative references

- SQLBL 1000, Structured language — Vocabulary and verbal forms

## Citation

SQLBL (2026). SQLBL 1019:2026, Signal Fidelity Terminology — Controlled Descriptor for Communication Quality. Edition 2. SQLBL/TC 19 Measurement and Conformance. Experimental standards corpus.