Standards & conformance
AGS 4.1 governs. The check is a conformance check.
This page states our standards position in plain terms. G& is a geotechnical data management and submission control platform. It runs a conformance check against the AGS 4.1 reference implementation. It is not the official AGS Validator, and it does not certify or approve a submission.
- Governing standard
- AGS 4.1 / 4.1.1
- AGS 4.2
- Referenced only
- Reference implementation
- python-ags4
- Terminal check
- Client validator
A / Governing standard
A file submitted as 4.1 leaves as 4.1.
- AGS 4.1 / 4.1.1 governs
- AGS 4.1 / 4.1.1 is the governing standard for all formal deliverables produced in G&. Groups, headings, units and code lists resolve against that dictionary version, and the version is recorded with the package.
- AGS 4.2 is referenced only
- AGS 4.2 is tracked as a reference. Adoption is not approved. Deltas between 4.1 and 4.2 are registered and maintained so they can be assessed, not applied by default.
- No silent version conversion
- G& does not convert files between AGS versions without an explicit, recorded instruction. A file submitted as 4.1 leaves as 4.1.
B / What the conformance check does
Structure, dictionary, integrity — reported in full.
- Structural and dictionary checks
- Group and heading validity, required groups, data types, unit and code-list consistency, and parent–child integrity, checked against the AGS 4.1 reference implementation (python-ags4, the library published by the AGS Data Format Working Group).
- Full findings, not a verdict
- Every finding is reported with severity, group, row and heading. Nothing is summarised away and nothing is suppressed to produce a clean result.
- Rule provenance is labelled
- AGS reference rules and platform rules — completeness thresholds and client overlays — are separated in the report, and each finding states which rule set raised it.
C / What the conformance check does not do
The limits are part of the specification.
These boundaries are stated deliberately. A platform that overstated its authority here would be harder to defend in a submission review, not easier.
- Not the official AGS Validator
- G& runs its own conformance check against the reference implementation. It is not the official AGS Validator and is not published by the AGS Data Format Working Group.
- Not a certification
- A clean conformance report is not a certification, an approval, or a guarantee that a submission will be accepted.
- Not a replacement for your step
- The receiving party's own validation step still applies in full. G& does not stand in for it.
- The client's validator is terminal
- Where a client or consultant runs their own validator, that result is the terminal check. G& is upstream of it.
D / Lossless handling
Nothing is dropped quietly.
This addresses a documented failure mode in geotechnical data exchange: reviewer toolchains built on older AGS revisions can destroy data on import without warning — truncated text fields, coerced identifiers, dropped groups. The loss is discovered late, in review, and is expensive to reconstruct.
- Ingest without silent loss
- Files are read as submitted. Text-type fields are preserved as text — leading zeros, alphanumeric identifiers and coded strings are not coerced into numbers.
- Import manifest
- Every import produces a manifest of what was read, what was retained, and what was rejected, with the reason for each rejection. Nothing is dropped quietly.
- File-vs-file comparison
- Two versions of the same package can be compared directly, group by group and heading by heading, so any change between issues is visible and attributable.
E / Authority chain
Who defines the format, and where we sit.
| Party | Role |
|---|---|
| AGS Data Format Working Group | Defines the format |
| Official AGS Validator / python-ags4 | Reference implementation |
| BGS AGS API | Widely used execution back-end |
| G& | Conformance-claiming implementation |
G& asserts conformance with the reference implementation. G& does not assert authority over the AGS format.
F / Standards referenced
Restated rules, with citations.
- BS 5930
- Code of practice for ground investigations — description and logging practice
- BS 1377
- Methods of test for soils for civil engineering purposes
- BS EN ISO 17892
- Geotechnical investigation and testing — laboratory testing of soil
- ISO 14688 / 14689
- Identification and classification of soil and of rock
- BS EN ISO 22475
- Sampling methods and groundwater measurements
- ASTM methods
- Test methods applied where the project specification calls for them
The platform stores restated rules with citations to the governing document. It does not reproduce licensed clause text. Where a project specification names a different method, that method is recorded against the result.
Read the rest of the position.
Data ownership and exit, security controls, and the AGS 4.1 readiness diagnostic set out the same commitments in operational detail.