/method/projection-records
Projection records
What a projection is
A projection is a derived, compressed view of an admitted record. Where the canonical body is the full reader-facing state of the record, a projection is a shorter or restricted view that the renderer can present alongside or instead of the canonical body in contexts where the full text is too long, too sensitive, or too detailed for the surface in question.
On GARPedia, projections render in the projection ledger inside the right-hand provenance rail. Each projection records its compression kind, compression ratio, generation timestamp, known-loss categories, reversibility, and optional notes. The reader sees the projection's existence and its shape, even if the projection itself is not the body currently being rendered.
Compression kind and compression ratio
The compression kind names the reduction operation the projection performed. The current canonical kinds are summary, abstract, extract, translation, and redacted_view; each of those names a different kind of reduction, with different implications for what was removed and what remains.
The compression ratio is an approximate ratio of the projection's length to the source record's canonical-body length, where 1.0 means no compression. The ratio is a guide for the reader, not a guarantee about information density. Two projections with the same compression ratio can differ substantially in what they preserve, which is why the known- loss categories field is recorded separately.
Known-loss categories
Every projection carries a known-loss array. Each entry names a category of information that the projection deliberately drops relative to the canonical body, in plain reader-facing language. A summary projection might declare loss of methodological appendices and per-paragraph normalization audit detail; a redacted-view projection might declare loss of every span anchored to a restricted source.
The known-loss array is reader-facing. It is not a complete inventory of differences, and it does not list every line that changed. It names the categories the projection was designed to drop, so that a reader who needs the dropped material knows to request the unprojected canonical body or one of the other projections.
Reversibility
Each projection carries a reversible_to_record flag. The flag is true when a governed export request against the source record can return the unprojected canonical body, and false when the projection is the only available form of the material for governance reasons. Reversibility is recorded as an explicit field rather than assumed, so that a reader who only ever sees the projection knows whether the source record is recoverable through governed channels.
GARPedia does not perform export requests from the public surface. The reversibility flag describes the underlying record's exportability through governed channels; the renderer's role is to surface the flag, not to operate the export.
Where projections appear
Projections appear in the ProjectionLedger panel inside the provenance rail on each record page. A record with no projections shows an empty ledger and a short note that the page reflects the full canonical body. A record with one or more projections lists them with their compression kind, ratio, known-loss categories, reversibility flag, and notes. The method panel at the foot of the page then explains the rules and posture under which the record was rendered, so the projections' existence appears alongside the rest of the governance picture.