18 AL/BC patterns: style, data-modeling, web-services, appsource, breaking-changes, performance, testing (#156)

* Add 18 community AL/BC patterns across style, data-modeling, web-services, appsource, breaking-changes, performance, and testing

Contributed by CURABIS ApS, generalized from patterns observed across real AppSource/PTE development. Each article follows the knowledge file format (frontmatter, Description/Best Practice/Anti Pattern, sibling .good.al/.bad.al samples).

* Address Jesper Schulz-Wedde's review on PR #156

- Rename 3 articles so their .good.al/.bad.al companion stems match
  (do-not-change-primary-key, testfield-required-setup-field,
  al-identifiers-english), fixing the R14 orphan-sample errors.
- do-not-change-primary-key.good.al: include Flow in the new table's
  own primary key so it actually models the discriminating dimension.
- al-build-output-must-not-pollute-project-root.md: drop the
  unsubstantiated AL0197 causal claim and the non-existent
  al.outputPath setting; reframe as build-artifact hygiene sourced
  from ALTool --outfolder / al_build outputPath.
- prefer-email-module.md: Email Message is Codeunit 8904, not a table;
  distinguish it from the underlying Sent/Outbox/Draft storage.
- file-datatype-saas.md: File.Open/Create/Read/Write fails to compile
  against a Cloud-scoped project, it does not compile and silently
  fail at runtime.
- namespace-must-be-verified-from-source.md: narrow to "resolve from
  the referenced object's source or symbols," since source-file line
  one is not the only authoritative source (symbol packages, comments
  before the namespace line).
- test-data-must-be-random-and-complete.md: drop "assume an empty
  database" and "collision-free" absolutes; reframe around
  independence from unrelated business records and reserving explicit
  values for scenario-defining inputs.
- binary-choice-must-be-boolean.md: scope to genuine true/false
  semantics, not mechanical two-member-enum-to-boolean conversion.
- document-report-word-layout.md: scope down to a sourced Microsoft
  Learn recommendation instead of an unconditional performance
  guarantee; cite the three Learn pages.
- Wire the new articles into their review skills' candidate-selection
  signals (file-datatype-saas, prefer-email-module,
  namespace-must-be-verified-from-source, var-parameters-require-an-
  addressable-variable) so they can actually enter a worklist.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* Fix dimension-management-wiring.md: ValidateShortcutDimCode and CreateDim
do not exist on the current DimensionManagement codeunit

Verified against microsoft/BCApps: the real master-table validation
procedure is ValidateDimValueCode (or ValidateShortcutDimValues when a
DimSetID is also needed), and the real document-side inheritance
procedure is GetDefaultDimID, not CreateDim. Caught from Jesper
Schulz-Wedde's review thread, which had been partially hidden by
GitHub's comment folding.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* Address second round of Jesper Schulz-Wedde's review on PR #156

- dimension-management-wiring.md/.good.al: split into the two distinct
  models the article was conflating - master data (Default Dimension
  records via ValidateDimValueCode/SaveDefaultDim) vs. transactional/
  document data (a single Dimension Set ID assembled via AddDimSource +
  GetDefaultDimID, verified against BCApps' ExchRateAdjmtProcess.Codeunit.al).
  Added a compiling document-table example alongside the existing master
  table one.
- Deleted api-page-flowfields-must-be-calcfields (.md/.good.al/.bad.al):
  Microsoft's own FlowFields documentation states a FlowField used as a
  control's direct source expression is automatically calculated on any
  page - no API-page exception is documented, and none could be
  reproduced.
- prefer-email-module.bad.al/.md: Codeunit Mail has no Send/GetErrorDesc
  members; fixed to the real current 7-argument CreateMessage signature,
  and corrected the claim that the legacy path "still runs" - its base
  implementation no longer sends anything, only raises integration events.
- check-post-line-batch-pattern.md/.good.al: reframed from a universal
  invariant to the standard shape, naming the real Gen./Item/CA/Res./Job/
  Insurance/Mfg. Item/FA Jnl.-Check Line/-Post Line/-Post Batch codeunits
  it's based on. Added the missing Check Line companion codeunit so the
  good fixture is internally complete.
- test-data-must-be-random-and-complete.good.al: removed leftover
  "collision-free" wording contradicting the already-corrected article text.
- fixed-choice-set-must-use-enum-not-integer.md: removed the reintroduced
  state-count heuristic ("the line is the state count"), aligned with
  binary-choice-must-be-boolean.md's semantics-based distinction.
- namespace-must-be-verified-from-source.md: removed the false claim that
  the compiler and AL Language Server use different namespace-resolution
  rules.
- intrinsic-al-functions-must-use-modern-casing.md: removed the unverified
  claim that PascalCase is the VS Code formatter's default output.

Worklist completeness: added cues for the 8 rules in data-modeling,
testing, performance, and web-services that had none (Jesper's explicit
ask), plus the same gap in all 7 style rules from this PR (not explicitly
named this round, but the identical systemic issue) - 15 cues total across
al-data-modeling-review.md, al-testing-review.md, al-performance-review.md,
al-web-services-review.md, and al-style-review.md.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* Fix remaining correctness issues from Jesper's 2026-09-15 re-review

- dimension-management-wiring: SaveDefaultDim's third argument is the
  shortcut dimension number (1-8), not the field's AL field ID; the
  fixture passed FieldNo(...) = 10. GetDefaultDimID's InheritFromDimSetID
  must be 0 when recomputing after the linking record changes, not the
  document's existing Dimension Set ID (which would retain the previous
  customer's leftover dimensions). Verified against
  DimensionManagement.Codeunit.al and BankDepositHeader.Table.al in the
  BCApps reference clone.
- check-post-line-batch-pattern: "Post Line writes exactly one line to
  the ledger" overclaimed - Gen. Jnl.-Post Line alone calls InsertGLEntry
  from a dozen call sites (balancing entry, VAT, currency rounding,
  deferrals) and can write several G/L Entries per journal line.
  Reworded to "posts exactly one journal line" and softened the
  "distinct, non-overlapping responsibilities" absolute.
- namespace-must-be-verified-from-source.bad.al: dropped the "resolves
  in a local build, fails in VS Code" comment (taught an inherent
  compiler/language-server disagreement that isn't real); reframed as
  stale/cached symbols, matching the prose fix already made.
- file-datatype-saas.good.al: replaced the deprecated 5-argument
  UploadIntoStream overload with the current 2-argument one, and
  actually staged through TempBlob as the article's own Best Practice
  instructs (the declared TempBlob variable was previously unused).
- test-data-must-be-random-and-complete: no longer treats a
  short-but-valid value as defective merely for being "underfilled" -
  AL field lengths are maxima, not minimums. Scoped to missing values
  or a scenario with an explicit length/format requirement (e.g. a
  truncation test). Updated the al-testing-review.md routing cue to
  match.
- stored-derived-fields-must-not-be-exposed-directly: stopped mandating
  source-field exposure as part of the core pattern: the good fixture
  exposed only one of the derived value's two inputs (Hours Used, not
  Budgeted Hours), making the claimed "so the consumer can verify it"
  impossible. Reframed as an optional, all-or-nothing addition and
  fixed the fixture to expose both inputs.

Rebased onto upstream/main to resolve conflicts in
al-breaking-changes-review.md, al-data-modeling-review.md,
al-performance-review.md, and al-style-review.md against merged PRs
#148 and #153; all sides' worklist tokens/cues retained.

* Fix remaining READ-convention sample links across this PR's 18 articles

The same plain-backtick "See sample: \`x.good.al\`." form fixed on
al-methods-limited-during-write-transactions (PR #161) turned up
repo-wide on 15 more of this PR's articles - Knowledge-Retrieval.ps1
requires the markdown-link form to associate a sample with its
article. All 16 fixed; the four local validators (frontmatter,
knowledge-index, knowledge-retrieval, review-fixtures, skill-index)
pass.

* Fix two merge-critical correctness issues from Jesper's 2026-09-22 review

- api-page-key-fields-must-be-editable-on-insert.good.al and
  stored-derived-fields-must-not-be-exposed-directly.good.al: both were
  writable API pages missing DelayedInsert = true, contradicting this
  repo's own api-page-delayedinsert-true rule - the canonical "good"
  samples were teaching code BCQuality itself flags.
- dimension-management-wiring.good.al: UpdateDimensionSetID exited
  early when Customer.Get failed, leaving the previous customer's
  shortcut dimension and Dimension Set ID in place - the same staleness
  bug the InheritFromDimSetID = 0 fix (from the prior review round) was
  meant to prevent, just triggered by a failed lookup instead of a
  successful one. Now clears the shortcut field and recomputes with an
  empty source list on a failed lookup too, so GetDefaultDimID
  correctly returns an empty Dimension Set ID instead of never running.

---------

Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>

microsoft/skills/review/al-appsource-review.md

@@ -52,6 +52,7 @@ The following targeted checks cover every current `appsource` article across the
 - A page or report that repository context identifies as a direct user entry point omits `UsageCategory` or sets it to `None` — `set-usagecategory-on-searchable-entry-points`. Do not select this article based only on object type; exclude supporting parts, dialogs, API pages, and objects intentionally reached through another page.
 - A `DateTime` assignment adds or subtracts a fixed duration to represent an assumed regional offset — `do-not-hard-code-time-zone-offsets`. Require contextual evidence such as an hour-sized constant, offset-oriented name, or time-zone comment; do not flag deadlines, schedules, or elapsed-time calculations.
 - For BC v27 or later, `app.json` adds or changes the `help` URL to a path deeper than two levels, or a changed Copilot/context-sensitive help arrangement would ground the app under an overly broad truncated parent — `keep-copilot-help-url-to-two-path-levels`.
+- Changed code declares or calls `File.Open`/`File.Create`/`File.Read`/`File.Write` in an app targeting Business Central Online — `file-datatype-saas`.
 
 Once the candidate worklist is known, resolve layer-precedence conflicts per READ. Drop lower-precedence files whose normative guidance (`## Best Practice` or `## Anti Pattern`) directly contradicts a higher-precedence candidate, and record each dropped file in `suppressed` with `reason: "layer-precedence"`. Files that would have been candidates but are hidden because their layer is disabled in consumer configuration are recorded with `reason: "configuration"`. Files that never became candidates are NOT recorded in `suppressed`.
 

microsoft/skills/review/al-breaking-changes-review.md

@@ -50,7 +50,9 @@ The following targeted checks cover every current `breaking-changes` article:
 - A published procedure changes parameter count/order/type/name, `var`, return type, or array shape instead of preserving the old signature and adding an overload — `do-not-change-published-procedure-signatures`.
 - A public procedure/event/interface exposes a credential or other sensitive value through `Text` or an externally callable contract — `do-not-expose-sensitive-data-through-public-api`.
 - Code already marked obsolete is expanded with new behavior instead of routing new callers to its replacement — `do-not-modify-code-already-marked-obsolete`.
-- A shipped table field is deleted, renamed, renumbered, or replaced without retaining the original field as `ObsoleteState = Pending` and migrating its data — `obsolete-table-fields-instead-of-deleting-them`.
+- A shipped table field is deleted, renamed, renumbered, or replaced without retaining the original field as `ObsoleteState = Pending` and migrating its data — `obsolete-table-fields-instead-of-deleting-them`. This owns AS0005 field-name changes; do not substitute the namespace article.
+- A published object's namespace changes between the base and changed source while its identity otherwise remains — `namespace-is-part-of-published-object-identity`. Do not apply it to a new, unshipped object or to an ordinary object-name change with no namespace change.
+- New or changed code calls `Codeunit Mail`'s `CreateMessage`/`Send`/`GetErrorDesc` instead of `Codeunit Email`/`Codeunit "Email Message"` — `prefer-email-module`.
 
 For `obsolete-table-fields-instead-of-deleting-them`, compare the baseline ID and name before emitting. When the original field remains under the same ID and name with `ObsoleteState = Pending`, and the replacement uses a new ID, the change follows the rule and must not be flagged.
 

microsoft/skills/review/al-data-modeling-review.md

@@ -54,6 +54,10 @@ The following targeted checks cover every current `data-modeling` article. Treat
 - A `Media` or `MediaSet` field is assigned directly between different table types or different field IDs instead of registering each shared item with `MediaSet.Insert` — `share-mediaset-items-with-insert-not-field-assignment`.
 - A custom document header assigns defaults outside an `InitRecord` boundary, calls `InitRecord` before assigning its number, or places UI-independent defaults only in a page trigger — `initialize-document-defaults-in-initrecord`.
 - Directed `Round` calls use `'<'` as mathematical floor or `'>'` as mathematical ceiling, especially where negative amounts are possible — `round-direction-symbols-use-magnitude`.
+- A new field is typed `Code`/`Text` and its `OnValidate` calls `DimensionManagement`/`DimMgt`, or a table adds Shortcut Dimension fields, a `Dimension Set ID` field, or `AddDimSource`/`GetDefaultDimID` — `dimension-management-wiring`. A master table calling `SaveDefaultDim` and a document/journal table computing its own `Dimension Set ID` are two different valid shapes; do not flag a master table for lacking a `Dimension Set ID` field or a document for lacking `SaveDefaultDim`.
+- A journal-based posting codeunit is added or changed and validation, Journal-table access, ledger writes, and user-interaction (`Confirm`/dialogs) all occur in one procedure or one codeunit, rather than split across `Check Line`/`Post Line`/`Post Batch`-shaped companions — `check-post-line-batch-pattern`. A document posting routine calling `Post Line` directly without a `Post Batch` companion is not this anti-pattern.
+- An existing, already-published table's `keys` block adds, removes, or reorders a field in its primary key or any `Clustered = true` key — `do-not-change-primary-key`. A new table defining its own key for the first time is not this anti-pattern; requires repository/publication context to know the table has already shipped.
+- Code reads a setup/configuration-table field inside a branch that has already decided the value is required, and blank/zero is handled with a fallback to a default rather than `TestField`/an equivalent guard — `testfield-required-setup-field`. A read that is genuinely optional in that branch, or one already guarded by `TestField`, is not this anti-pattern.
 
 Once the candidate worklist is known, resolve layer-precedence conflicts per READ. Drop lower-precedence files whose normative guidance (`## Best Practice` or `## Anti Pattern`) directly contradicts a higher-precedence candidate, and record each dropped file in `suppressed` with `reason: "layer-precedence"`. Files that would have been candidates but are hidden because their layer is disabled in consumer configuration are recorded with `reason: "configuration"`. Files that never became candidates are NOT recorded in `suppressed`.
 

microsoft/skills/review/al-performance-review.md

@@ -58,6 +58,7 @@ Apply these targeted cues even when simple token overlap would rank the article
 - Worklist `job-queue-on-hold-does-not-stop-running-work.md` when a running job queue handler polls the entry's `Status` or `On Hold` value as a cancellation signal. Exclude application-owned stop requests that are checked before every bounded unit of work, including the first, when completed work and its checkpoint remain consistent and resume logic clears the request.
 - Worklist `job-queue-category-code-serializes-conflicting-jobs.md` when two or more job queue entries in the same company are shown by the changed context to require mutual exclusion but have empty or different Job Queue Category Codes. Do not infer a conflict merely because jobs touch the same tables, and do not recommend a category to coordinate across companies, environments, or workers outside the job queue dispatcher.
 - Worklist `store-scheduled-task-id-to-avoid-duplicate-tasks.md` when `TaskScheduler.CreateTask` runs from initialization, login, setup, or another repeatable path without persisting its returned GUID and checking it with `TaskScheduler.TaskExists` before creating a replacement. Exclude one-shot creation and correctly persisted check-before-create flows; concurrent callers still require serialization around that sequence.
+- A new or changed report object whose usage/name/caption identifies it as a single-record document (invoice, statement, order confirmation) sets or retains `DefaultRenderingLayout = RDLC` — `document-report-word-layout.md`. Do not worklist this from a tabular/list report with heavy aggregation or calculated columns; RDLC/Excel remains the better fit there.
 
 These targeted inclusions and exclusions override generic token overlap. Do not retain an excluded article solely because the diff contains one of its keywords.
 

microsoft/skills/review/al-style-review.md

@@ -40,8 +40,8 @@ Discard files that are not applicable. Retain conditionally applicable files onl
 Narrow the relevant files to the subset that applies to the changes under review. For each relevant file, compute overlap against:
 
 - Changed AL objects — especially API pages (`PageType = API`), tables and pages declaring Labels/TextConsts, codeunits issuing `Error`/`Message`/`Confirm`, and any file whose name violates the `<ObjectName>.<ObjectType>.al` convention.
-- Changed declarations, weighted toward `: Label '...'`, `: TextConst '...'`, temporary record variables, `DateFormula` declarations and their `Evaluate` call sites, error-handling call sites, and API declarations.
-- Tokens extracted from the diff (`Label`, `TextConst`, `Locked`, `Comment`, `MaxLength`, `temporary`, `DateFormula`, `Evaluate`, `CalcDate`, `APIPublisher`, `APIGroup`, `APIVersion`, `EntityName`, `EntitySetName`, `DelayedInsert`, `FieldCaption`, `TableCaption`, `FieldName`, `TableName`, `Page.RunModal`, `Report.Run`, `StrSubstNo`).
+- Changed declarations, weighted toward `: Label '...'`, `: TextConst '...'`, temporary record variables, option fields, `DateFormula` declarations and their `Evaluate` call sites, error-handling call sites, API declarations, and codeunit-internal method calls.
+- Tokens extracted from the diff (`Label`, `TextConst`, `Locked`, `Comment`, `MaxLength`, `temporary`, `DateFormula`, `Evaluate`, `CalcDate`, `OptionMembers`, `OptionCaption`, `APIPublisher`, `APIGroup`, `APIVersion`, `EntityName`, `EntitySetName`, `DelayedInsert`, `FieldCaption`, `TableCaption`, `FieldName`, `TableName`, `Page.RunModal`, `Report.Run`, `this.`, `StrSubstNo`, `namespace`, `using`, `var `).
 
 A file enters the candidate worklist when its `keywords` intersect the extracted tokens or its topic (derived from the index entry's `path`, `title`, and `description`) matches a changed object or declaration. Read an article's full file — its `## Best Practice` / `## Anti Pattern` bodies — only after it makes the worklist; candidate selection uses the index alone.
 
@@ -51,6 +51,14 @@ Apply these high-signal mappings before fuzzy topic ranking:
 
 - A `Label` or `TextConst` contains multiple or ambiguous placeholders but has no `Comment`, or its Comment does not explain every placeholder — `label-comment-explains-placeholders.md`. A single placeholder whose meaning is explicit in the text, such as `Customer %1`, is allowed without a Comment and must not be flagged.
 - A normal two-argument `Evaluate` has a resolved `DateFormula` destination and a hard-coded non-angle-bracket date-formula literal, directly or through a visible constant — `dateformula-evaluate-needs-language-independent-literals.md`. Do not use this cue for dynamic/localized external input, already invariant `<...>` input, or direct `CalcDate(Text, ...)` calls.
+- `function-call-parentheses-required.md` applies only to a zero-argument invocation written without `()`. Never worklist it from an invocation that already has parentheses or supplies arguments, including `Error(Label, Arg1, Arg2)`.
+- A new `.app` build artifact appears at the project root or another unversioned/arbitrary location, or is added to source control alongside the AL source that produced it — `al-build-output-must-not-pollute-project-root.md`. A deliberate `--outfolder`/`outputPath` destination added to `.gitignore` is the compliant shape, not the signal to flag.
+- A new or renamed AL identifier (variable, procedure, parameter, field, object, enum value, or label identifier) contains non-English words — `al-identifiers-english.md`. A caption, tooltip, or other user-facing text value in a non-English language is not this anti-pattern; only the identifier itself is in scope.
+- A field or variable is typed `Boolean` and its two possible values are genuinely named domain alternatives (a status pair like Inbound/Outbound, Debit/Credit, Buy/Sell) rather than a true/false predicate, or an `Option`/`Enum`/`Integer` models a domain concept that is intrinsically a yes/no flag — `binary-choice-must-be-boolean.md`. The signal is a semantic mismatch between the type and the domain concept, not the current number of states.
+- A field or variable is typed `Integer` with the meaning of each value tracked only in a comment, or an `Enum` with more than two members is proposed as `Boolean`-like — `fixed-choice-set-must-use-enum-not-integer.md`. Do not flag a genuinely two-state `Enum`/`Option` for having "too few" members; that overlaps `binary-choice-must-be-boolean.md` instead when the domain is a true/false predicate.
+- A new `using` directive is added for an existing AL object without the diff also showing that object's own `namespace` declaration or a symbol-package lookup backing the choice — `namespace-must-be-verified-from-source.md`. Require repository/dependency context; a single new `using` line cannot itself prove whether the namespace was verified or guessed.
+- An intrinsic/built-in AL function call (`MESSAGE`, `ERROR`, `CONFIRM`, `STRSUBSTNO`, etc.) is written in ALL-CAPS or another non-PascalCase form — `intrinsic-al-functions-must-use-modern-casing.md`.
+- A procedure call passes a literal or a computed expression (not a caller-scope variable) to a parameter position the callee declares `var` — `var-parameters-require-an-addressable-variable.md`. This is a compile-time-guaranteed shape; flag it only when the callee's declared signature is visible in the diff or resolvable from context.
 
 Once the candidate worklist is known, resolve layer-precedence conflicts per READ and record suppressions.
 

microsoft/skills/review/al-testing-review.md

@@ -51,6 +51,7 @@ The following targeted checks cover every current `testing` article. Treat each
 - Test fixture code manually calls `Init`/`Insert`, invents keys or prerequisite records, or bypasses available `LibrarySales`, `LibraryPurchase`, `LibraryERM`, `LibraryInventory`, `LibraryRandom`, or equivalent library codeunits — `use-library-codeunits-for-test-fixtures`.
 - `asserterror` is added or changed without a following `Assert.ExpectedError`, `Assert.ExpectedErrorCode`, or a purpose-built assertion such as `ExpectedTestFieldError` — `asserterror-needs-expectederror-and-code`.
 - A test path raises UI and `[HandlerFunctions(...)]` does not match the invoked handlers, or the test has no meaningful evidence of the UI result (for example, it treats a Boolean set before the action as proof of success) — `ui-handlers-in-tests`. A capture/reset/assert-after-`RunModal` pattern is valid. Enqueue/dequeue and `AssertEmpty` are required only when order, count, text, replies, or a scripted sequence is part of the contract. Only nonoptional handlers have to execute: a listed handler declared `[SendNotificationHandler(true)]` or `[RecallNotificationHandler(true)]` is optional by design, so do not treat it as unmatched when the run never raises the notification.
+- A test's `[GIVEN]`/setup looks up a hardcoded code/number/name assumed to already exist instead of creating it, leaves a mandatory field on a created record empty, uses a value that doesn't satisfy the scenario's own explicit length/format requirement (for example a truncation test whose value never exceeds the field), or a scenario-defining value (amount, quantity, percentage, date, threshold, rounding precision) is generated/randomized instead of an explicit chosen value — `test-data-must-be-random-and-complete`. Generating incidental fixture values (identifiers, names, descriptions) via the standard library codeunits is the compliant shape, not the signal to flag, and neither is a short-but-valid value in an otherwise-unremarkable field.
 
 Once the candidate worklist is known, resolve layer-precedence conflicts per READ. Drop lower-precedence files whose normative guidance (`## Best Practice` or `## Anti Pattern`) directly contradicts a higher-precedence candidate, and record each dropped file in `suppressed` with `reason: "layer-precedence"`. Files that would have been candidates but are hidden because their layer is disabled in consumer configuration are recorded with `reason: "configuration"`. Files that never became candidates are NOT recorded in `suppressed`.
 

microsoft/skills/review/al-web-services-review.md

@@ -40,6 +40,8 @@ Narrow the relevant files to the subset that applies to the changes under review
 - The changed AL object names and types — especially pages declared with `PageType = API`, API page `part` controls, queries declared with `QueryType = API`, and procedures that expose bound actions.
 - The changed properties and triggers, weighted toward API page metadata (`APIPublisher`, `APIGroup`, `APIVersion`, `EntityName`, `EntitySetName`, `ODataKeyFields`, `SourceTable`, `SourceTableTemporary`), navigation metadata (`SubPageLink`, `Multiplicity`, and visible singleton or collection semantics), CRUD guards (`InsertAllowed`, `ModifyAllowed`, `DeleteAllowed`, `Editable`), the `OnOpenPage` trigger, and `OnValidate` triggers on exposed fields.
 - Webhook subscriber handlers and subscription lifecycle code, especially code that creates or renews subscriptions, handles `validationToken`, schedules from `expirationDateTime`, or targets resources whose eligibility is visible in the diff.
+- An API page (`PageType = API`) with `InsertAllowed = true` lists a field in `ODataKeyFields` and that same field control sets `Editable = false` — `api-page-key-fields-must-be-editable-on-insert.md`. A system-generated key such as `SystemId` marked read-only is not this anti-pattern.
+- An API page exposes a field via `Rec` directly, and that field is a stored value computed from other fields inside an `OnValidate` trigger rather than a FlowField recalculated in `OnAfterGetRecord` — `stored-derived-fields-must-not-be-exposed-directly.md`. Exposing a genuine FlowField, or a value already recalculated in `OnAfterGetRecord`, is not this anti-pattern.
 - Tokens extracted from the diff that relate to API surface and behaviour (`PageType`, `QueryType`, `API`, `api-page`, `page-part`, `APIPublisher`, `APIGroup`, `APIVersion`, `EntityName`, `EntitySetName`, `ODataKeyFields`, `SystemId`, `SubPageLink`, `subpagelink`, `Multiplicity`, `multiplicity`, `Many`, `ZeroOrOne`, `SourceTableTemporary`, `Job Queue Entry`, `webhook`, `webhookSupportedResources`, `webhook-supported-resources`, `subscriptions`, `notificationUrl`, `validationToken`, `validationtoken`, `expirationDateTime`, `expirationdatetime`, `ServiceEnabled`, `WebServiceActionContext`, `SetActionResponse`, `ReadIsolation`, `IsolationLevel`, `ReadCommitted`, `InsertAllowed`, `ModifyAllowed`, `DeleteAllowed`, `Editable`, `SourceTable`).
 
 A file enters the candidate worklist when its `keywords` intersect the extracted tokens or its topic (derived from the index entry's `path`, `title`, and `description`) matches a changed object type. Read an article's full file — its `## Best Practice` / `## Anti Pattern` bodies — only after it makes the worklist; candidate selection uses the index alone.