From an Access form to a field

Begin with the owning surface and the control binding.

A form or report can declare a RecordSource. A bound control can declare a ControlSource. Together they form the shortest useful static trail: control → owning surface → record source → query output or table field candidate. A direct field binding is stronger than a textual resemblance because the relationship retains stable identities, rule ID, evidence tier, coverage label, extractor version, and bounded design coordinates.

The trail is still a declaration. It does not say that the form opened, a record was loaded, a user edited the control, or a write occurred. If the source identity is missing or ambiguous, TraceMap keeps the candidate at review tier or emits a Tier 4 gap instead of picking a same-named object.

Lookup controls have two different data stories.

A combo box or list control may use RowSource and RowSourceType to describe the values shown in the lookup. Its BoundColumn and bounded projection ordinal indicate which projected value could become the control value. That lookup-population path is distinct from the control’s persistence binding through ControlSource and the form’s RecordSource.

Keeping those branches separate prevents a plausible wrong join. A display column is not automatically the stored column. An ordinal beyond the known projection, an incomplete source declaration, a dynamic row source, or an ambiguous query output becomes an explicit gap. Bounded fan-out limits keep a broad lookup from producing an unreviewable cloud of candidates.

Subforms add correspondence, not runtime navigation.

A subform or subreport control can declare a source object together with master and child link fields. TraceMap can retain the surface relationship and bounded master/child correspondences as static candidates. That helps a reviewer move from a parent surface toward the child surface’s record source and fields while preserving which declaration supplied each hop.

The metadata does not establish that navigation occurred, that parent and child values matched at runtime, or that referential integrity was enforced. Missing pairs, duplicate identities, unsupported expressions, and incomplete catalogs remain unresolved rather than being normalized into a single convenient answer.

Saved-query outputs can narrow a field candidate.

When a saved query exposes bounded output declarations and an exact static source-field candidate, the trail can continue from a form or lookup source through the query output toward a table field. The evidence identifies the output position and the source relationship that supports the candidate. It does not publish the underlying query text.

Action queries, crosstabs, parameters, aliases, calculated outputs, and incomplete catalogs can weaken or interrupt that path. TraceMap distinguishes exact declarations from static candidates and illustrative alternatives. Dynamic SQL and names that cannot be resolved safely stay Tier 4 unknown; an empty trail does not prove that no data dependency exists.

Calculated expressions widen the question carefully.

A calculated control or query output may reference fields, controls, or supported domain-function categories. TraceMap can project bounded dependencies where the source-neutral expression evidence provides an exact candidate. Those relationships help a reviewer see that the displayed value may depend on more than the direct persistence binding.

Unknown functions, unsupported syntax, dynamic references, ambiguous control scope, and incomplete projection remain gaps. A calculated dependency is not evidence that the expression evaluated successfully, that its result was correct, or that every possible input was represented.

Event evidence remains a candidate, even when the name is exact.

A populated event property can point to an exact same-module procedure candidate. Protected VBA projection can also retain bounded static categories such as a literal conditional RowSource assignment, with hash-safe branch context rather than the source body. That can add a second possible lookup source to the review trail.

Exact identity does not prove event firing, lifecycle order, selected branch, user navigation, or runtime reachability. Dynamic handlers, embedded macros, unsupported branches, and unresolved references remain visible gaps. The candidate is useful because its limitation stays attached, not because TraceMap upgrades it into observed behavior.

Read the composed trail hop by hop.

A representative public-safe trail can be read as: lookup population candidate → bounded projected column → control value candidate → direct control persistence binding → owning form record source → saved-query output candidate → table field candidate. A conditional event assignment may appear as an alternative lookup-population branch. A subform may add a separate master/child correspondence toward another surface.

Each hop carries its own strength. Direct declared bindings can use Tier 2 structural evidence. Expression or source-text candidates may be Tier 3 syntax or textual evidence. Missing, ambiguous, unsupported, incomplete, or capped relationships are Tier 4 unknown. The composed path cannot be stronger than its weakest required hop.

Five rule families keep the story auditable.

legacy.access.ui-surface.v1 covers form, report, and control inventory. legacy.access.binding.v1 covers source and binding declarations. legacy.access.vba.v1 covers protected static VBA candidates. legacy.access.event-binding.v1 covers event-property to same-module procedure candidates. Finally, legacy.access.screen-data-flow.v1 composes bounded trails from already persisted evidence and carries cycles, fan-out, coverage, and gap state forward.

The evidence model explains the tiers, and the gap guide explains why uncertainty must remain visible. Read the Access acquisition boundary first: the lineage story depends on protected source-neutral evidence and does not widen that safety contract.

Turn the trail into owner questions.

A manager can ask which controls have direct bindings, which paths depend on query outputs or expressions, which lookup projection is only a candidate, where subform correspondences are incomplete, which event alternatives are unresolved, and which owner can validate the runtime behavior. Use the manager proof path, static-versus-runtime guide, capability index, change-review use case, and limitations to keep that handoff bounded.

What the lineage does not prove.

The trail does not prove runtime execution, query results, selected branches, event firing, user navigation, row access, data correctness, effective permissions, production behavior, complete coverage, successful reconstruction, release approval, or operational safety. It does not replace an Access owner, database owner, testing, runtime observation, security review, or human approval.

Public material includes no database file, serialized definition, SQL, VBA or macro body, source snippet, credential, connection material, machine-specific path, private object identity, analyzer dump, or private validation detail. No LLM, embedding, vector, or prompt classification is used to invent the lineage.

The result is a reviewable candidate path, not a reconstructed app.

TraceMap can show how declared Access bindings and bounded static candidates connect a visible design control toward query and persisted-field evidence. The value comes from seeing the exact hops, alternatives, evidence tiers, and gaps together—while leaving runtime truth with the owners and systems that can actually observe it.