llm-ingestion-okf/docs/2026-09-10-k3-runde12-pdf-outlines.md

# K3 round 12: the PDF shipped a finished structure index and the build discarded it unopened

`okf build` reads a PDF's page text and recovers boundaries from the shape of
that text. It never opens the file's `/Outlines` bookmark tree. On a document
whose publisher wrote one, that is the difference between guessing the
structure and being told it.

This round adds `--pdf-outline`, **off by default**, which cuts a PDF at the
boundaries its own bookmark tree declares. It is a segmentation arm: the
extracted text is byte for byte the same either way.

Every number below carries its denominator. The two that matter most are that
the fasit is the **publisher's own** structure, and that it describes **one
document, one format, one publisher** (§ 7).

## 0. Three divergences from the numbers this round was handed

The order and the incoming FYI both rest on `vegnormal-okf`'s SK2 measurement.
Its headline reproduces here **exactly** -- 1 967 of 2 761, depth 1 `0 of 28`,
false positives 163 of 2 182, 794 of 794 misses present in the text -- both
against SK2's own bundle and against one rebuilt on this repository's HEAD
(§ 2). Three characterisations around it do not survive re-measurement.

**(a) "No okf concept directory is a bare number" is a property of that
BUNDLE, not of okf.** The claim is what makes 81 of 2 761 fasit rows
unreachable for SK2's pair key, and all 28 depth-1 rows sit in that group. It
is true of the arm-off bundle: **0 of its directories** is a bare integer.
It is false of okf: with the arm on, **57 of 2 738** directories are, because
`_split_outline_title` reads the same bare one-or-two-digit grammar Arm D
already carries. The rows were unreachable because the boundaries were never
opened, not because the id form forbids it.

**(b) The corrected instrument does NOT lift the arm-off number.** The
correction -- accept a hit when the concept's own normalised title equals the
fasit's, alongside the pair key -- was expected to show that "depth 1: 0 of 28"
was partly an instrument artifact. Measured on the arm-off bundle it changes
**1 967 to 1 967** and depth 1 stays **0 of 28 in both forms**. So on the
shipped default that row was a real segmentation hole measured with an
instrument that *could* have reached it, and not only an artifact. The
correction earns its keep on the arm-**on** bundle, where it moves 2 737 to
2 759 and depth 1 from 12 of 28 to 28 of 28 (§ 3).

**(c) The 145 truncated titles and the 65 contents duplicates reproduce as
described**, and both are closed as a side effect rather than as separate work
(§ 3). They are re-characterisations of SK2's own numbers, not new
measurements on new material.

## 1. Where the gap is

- 794 of 794 missed STS titles have their heading text **present** in the
  extracted text; 0 of 794 are absent. The gap is segmentation, not
  extraction.
- The file carries an `/Outlines` tree of **2 763 nodes**. All **2 763 of
  2 763** resolve to a page index, and all **2 763 of 2 763** carry an `/XYZ`
  destination with a non-null `top`. After `re.sub(r"\s+","",s).lower()`,
  **2 761 of 2 761** STS titles match a node exactly; without the
  normalisation, 1 of 2 761.
- **Three holes, not one**, and the tree closes all three: the boundary that is
  never opened (794 of 2 761); the title cut short at the PDF's line break
  (145 of the 163 "false positives" and 81 of the 794 "misses" are this -- a
  bookmark title does not come from the page, so it is complete); and the table
  of contents becoming a second set of concepts (65 directories carrying both a
  contents copy and a body section under one id -- a bookmark's destination
  page *is* the body).

## 2. Reproduced before anything was built on it

| row | SK2 (`de9564d`) | this HEAD, arm off |
|---|---|---|
| boundaries | 1 967 of 2 761 (71.2 %) | **1 967 of 2 761 (71.2 %)** |
| depth 1 … 7 | 0/28 · 59/118 · 410/500 · 913/1141 · 551/868 · 31/97 · 3/9 | **identical** |
| false positives | 163 of 2 182 | **163 of 2 182** |
| misses present in the text | 794 of 794 | **794 of 794** |
| directories with two concept files | 132 of 2 050 | **132 of 2 050** |
| bare-integer directories | — | **0** |

`git log de9564d..HEAD -- extract.py propose.py` names exactly one commit
(`732f84d`, the HTML extractor), so the PDF path was unchanged between the
bundle SK2 measured and this tree -- and the rebuild confirms it rather than
resting on it.

## 3. The arm, measured

Built with `okf build … --pdf-outline`, same input, same epoch stamp.

| row | arm off | arm on (SK2's instrument) | arm on (corrected) |
|---|---|---|---|
| **boundaries** | 1 967 of 2 761 | 2 737 of 2 761 (99.1 %) | **2 759 of 2 761 (99.9 %)** |
| depth 1 | 0 of 28 | 12 of 28 | **28 of 28** |
| depth 2 | 59 of 118 | 116 of 118 | **118 of 118** |
| depth 3 | 410 of 500 | 499 of 500 | **500 of 500** |
| depth 4 | 913 of 1 141 | 1 140 of 1 141 | **1 141 of 1 141** |
| depth 5 | 551 of 868 | 866 of 868 | **868 of 868** |
| depth 6 | 31 of 97 | 95 of 97 | **95 of 97** |
| depth 7 | 3 of 9 | 9 of 9 | **9 of 9** |
| **titles identical to the STS title after `NORM`** | — | — | **2 761 of 2 761** |
| **false positives** | 163 of 2 182 | 25 of 2 762 | **3 of 2 762** |
| **directories with two concept files** | 132 of 2 050 | **2 of 2 738** | (same) |
| concepts in the front matter (page < 68) | 72 of 2 182 | **2 of 2 762** | (same) |
| concepts | 2 182 | **2 762** | (same) |
| K3-9: ends in a digit | 16 of 99 | 99 of 99 | **99 of 99** |
| K3-9: opens with a numbering token | 1 967 of 2 739 | 2 737 of 2 739 | **2 737 of 2 739** |
| K3-9: unnumbered | 0 of 22 | 0 of 22 | **22 of 22** |

The gate was **2 700 of 2 761** with the corrected instrument; the result is
2 759, and the ceiling is 2 761.

**The distance from the ceiling, named row by row rather than left as a
remainder.** Two fasit rows are missed, and they are the *same two nodes* the
false-positive column counts from the other side: `36.7331 48V strømforsyning
PoE` and `36.7332 24V strømforsyning`. The publisher's bookmark for each omits
the numbering token the STS `<title>` glues on, so the concept lands with no
number directory and the pair key cannot reach it. Both sections exist as
concepts with the right body; only the address differs. The third false
positive is the tree's own **root node**, `R761 Prosesskoden` -- one candidate,
the document's own title.

**The two remaining directories with two concept files are not contents
duplicates.** They are `11` and `12`, and each holds two genuinely distinct
declared sections that share a number: `11 ARBEIDSSTIKNING, TEKNISK KONTROLL`
(page 183) beside `11 Oversikt over prosesser` (pages 99–181), and the same
shape at 12. The 65 contents-copy pairs are **0**. The collision that remains
is the publisher reusing a number in two chapters, which is a different
mechanism and is not closed by anything here.

**Depth 6 stays 95 of 97 in both instrument forms.** The publisher's own tree
and the publisher's own STS disagree about four nodes: the tree's levels 2..8
hold 28/118/500/1141/**872**/**93**/9 against the STS depths 1..7 at
28/118/500/1141/**868**/**97**/9. The mapping is level minus one on five rows
and off by four on two of them, so the level is read from the tree and reported
as declared rather than normalised (`OutlineMark.level`). Reporting a depth-1
row as `28 of 28` because a `+1` shift was *assumed* would be the same failure
`0 of 28` was.

### 3.1 The bridge, both routes, with denominators

A bookmark states a page and a y position; a candidate needs a line index.
**2 706 of 2 761 bookmarks share a destination page with another bookmark**, so
the page alone is never a cut point.

- **Y route (primary).** `page.extract_text_lines()` carries a `top` per line.
  It requires the line splitting to be the one `page.extract_text()` produced,
  which is an assumption and is therefore CHECKED per page: measured **701 of
  701 pages identical**, and the check ships, so a page where it fails uses the
  title route instead of guessing.
- **Title route (fallback).** The normalised bookmark title, searched in the
  destination page's own lines: **2 762 of 2 763** resolved.
- **They disagree on 0 of 2 762.** Swept over tolerances 0, 1, 2, 3, 5, 8 and
  12 pt, the agreement is **flat at 2 762 with 0 disagreements from 0 to 8 pt
  and collapses to 924 at 12 pt** (the document's line spacing). Because 0 pt
  is already exact, the rule ships with **no tolerance constant at all** -- the
  first line at or below the destination.
- The first naive rule -- *nearest* line -- was wrong on **1 840 of 2 762**
  nodes, one line early every time, because `/XYZ top` sits above the heading.
  It is recorded because it produced a plausible-looking bundle.

**Provenance.** For **2 762 of 2 762** concepts, the first page of
`source_pages` equals the bookmark's own destination page. `source_units`
still indexes exactly the string `extract_text` returned: the arm moves
boundaries, never units. A PDF concept's address still names the page range
its span covers -- now the range the publisher's own bookmark opened.

### 3.2 Consumption

Fasit presence was validated against the bundle **before** any rank was read.

| | arm off | arm on |
|---|---|---|
| fasit present in the bundle | 4 of 7 | **7 of 7** |
| hit@1 · hit@8 · hit@50 (default `k`) | 1/6 · 2/6 · 4/6 (SK2) | **3/6 · 5/6 · 5/6** |
| hit@1 · hit@8 · hit@50 (`k` = 50) | — | **3/6 · 5/6 · 6/6** |
| payload slots taken by the front matter | 0 of 8 (SK2) | **0 of 8, all eight questions** |

S3, S4 and the known-positive existed in no bundle before, because the section
that answers them never became a boundary.

**The known-positive is not delivered at default `k`, and that is stated rather
than rounded.** `1 Bruksområder for Prosesskoden` is a real 1 827-byte concept
now, reading as the answer to the question asked of it, and it ranks **13** --
delivered at `k` = 50, not at `k` = 8. SK2 reported it as `null` because the
boundary did not exist. The segmentation half of that row is closed; the
ranking half is not, and no part of this round touches ranking.

`S5` (`84.3 Armering`) is the one row still missing at `k` = 8: rank 11 at
`k` = 50, with `Armering av betonghvelv` at rank 1. `Armering` occurs nine
times in this structure, and that collision is in the ranking, not the bridge.

### 3.3 Cost

| | arm off | arm on |
|---|---|---|
| wall (`/usr/bin/time -l real`) | 119.22 s | **183.31 s** (+53.8 %) |
| peak RSS | 3 410 038 784 B = **3 252 MiB** | 3 409 002 496 B = **3 251 MiB** |
| times the PDF's pages are parsed | 1 | 1 |
| times the file is opened | 1 | 2 |

`/usr/bin/time -l` on macOS reports maximum resident set size in **bytes**, not
KB; both figures above are the byte value converted. Neither is a 2×
increase. SK2 measured the arm-off build at 180.50 s on their machine against
119.22 s here, so the honest comparison is the pair measured on one machine.
The extra open reads the bookmark tree and the line geometry; the page text
comes from the memoised extraction pass and is not re-rendered.

**No new dependency.** `pdfminer.six` 20260107 already ships under
`pdfplumber` in the existing `[extract]` extra, and exposes
`PDFDocument.get_outlines()`. `uv.lock` and `[extract]` are untouched;
`pypdf` is not introduced.

## 4. Nothing else moved, and it is measured rather than argued

- **`~/okf-test/dokumenter`, three ways: identical.** A build from a frozen
  `git archive` export of `8e19179`, a build on this tree with the arm off, and
  a build on this tree with the arm **on** -- `diff -r` is empty between all
  three. 52 md / 26 concepts, 0 of 5 rejected. Both PDFs there carry no
  `/Outlines`, which is what makes the third comparison a real control.
- `okf project` is still byte-equal to `okf build` (`diff -r` empty), and the
  new flag's argparse default and Python signature default agree -- the test
  that compares every same-typed parameter covers it.
- `okf skill` + `okf consume` + `okf check --skill … --payload …`:
  **conformant, 15 rules over 8 excerpts and 18 withheld entries, 0 findings.**
- The pinned K2 bundle's concept count, per-row hit@8 ranks and all three
  known-negatives are unchanged: the arm is off by default and the arm-off code
  path is byte-identical.
- **The 12-position reference is untouched by the shipped default** and stays
  `pdf` 7 of 8, `docx` 3 of 3, in both readings of the `xlsx` fasit
  (`|F|` = 11 → 10 of 12, `|F|` = 12 → 11 of 12). This is byte-identity, not a
  re-score.

**Reach, and the number that decides whether the default should move.** Of the
eight `pdf` positions on the reference, **1 of 8** carries a usable bookmark
tree (position 9, 11 nodes). One more (position 0) carries a tree whose two
nodes both fail to resolve -- the drop-and-count branch firing on a real
document rather than only on a fixture. The other six carry none.

With the arm on, position 9 goes from **4 concepts to 11**, and the eleven are
the document's own chapter names (`Innledning`, `Organisering av prosjektet`,
`Risikoforhold og spesifikke tiltak`, `Fremdriftsplan`, `Vedlegg 1: …`) --
seven chapters the extracted text never showed as headings at all. The
operator's cross for that position says a unit is a top-level chapter and the
free text says "ville jeg hatt hvert kapittel". Whether 11 is nearer that than
4 depends on an `|F|` the sheet does not define, because the sheet's own
"document's disposition" section could only list the four the text showed.
**That is an operator question and this round does not answer it.**

## 5. What did NOT move

No HTML change, no OCR, no consumption change, no new fasit, no new corpus, no
`.xml`/NISO-STS extractor, no change to Arm D (`--outline-run`/`--outline-gate`
are a text heuristic over numbered lines and are a different mechanism
entirely), no re-rating of the reference positions, no `--bold-title` move, no
version bump, no tag, no push. `uv.lock` and `[extract]` untouched. The
default did not move.

## 6. The tests, and what each one is for

`tests/test_pdf_outline.py`, over two hand-laid fixtures built by
`tests/fixtures/make_fixtures.py` -- no library's output, objects laid out by
hand, xref offsets computed from the emitted bytes (`outlined-krav.pdf`
2 073 B, `outline-broken-dest.pdf` 1 014 B).

- **Three levels, not two.** A two-level tree cannot tell "the level the node
  declares" from "one below the root".
- **The line, not the page.** The fixture's last page carries four lines and
  its second bookmark points at the third, so a bridge that resolved to the
  page and stopped would fail visibly instead of looking like it worked.
- **No `/Outlines` is not an error.** `PDFNoOutlines` yields no marks, no
  count, and identical behaviour.
- **An unresolvable `/Dest` is dropped and counted**, never fabricated and
  never a refusal.
- **An empty mark list leaves every other rule untouched** -- "this file has no
  index" and "propose nothing" must not collapse into one answer.
- **A declared section with no prose of its own survives.** The orphan check
  asks whether anything stands under a candidate's first line: the right
  question for a heuristic's guess, the wrong one for a publisher's
  declaration. Measured: **683 of 2 762** marks are container sections, and
  applying the check scores **2 079** instead of 2 759.

## 7. Honesty limits

- **The instrument was run in two forms and the two answer different
  questions.** SK2's pair key `(numbering token, normalised residual title)`
  cannot reach **81 of 2 761** fasit rows -- 59 with a dotless token, 22
  unnumbered -- and all 28 depth-1 rows are among them. Every percentage above
  says which form it rests on, and the gate was set at **2 700**, not at the
  ceiling 2 761, precisely because of those 81. The corrected form lives in a
  scratch copy of SK2's script; `vegnormal-okf` was read and never written, and
  the correction is offered to them, not applied on their behalf.
- **The fasit is the publisher's own STS structure.** "The right boundary" is
  therefore defined by the publisher, not by what is useful to a reader. A
  reader might well want 2 761 sections merged into far fewer.
- **The denominator 2 761 is CHOSEN.** The document has 7 715 `<sec>`; 4 954 of
  them carry a letter-point label (`a)`, `c)`) inside a process description and
  0 of those 4 954 is a process number. Measuring against 7 715 would answer a
  different question.
- **Matching is exact after normalisation.** A boundary set one word away from
  the source title counts as a miss. That is what makes 2 759 credible and also
  what makes it a floor rather than a satisfaction score.
- **One document, one format, one publisher.** R761 is a guideline with 2 739
  of 2 761 titles numbered in a strict hierarchy. A running prose document
  would measure something else, and this round has no such document with a
  fasit.
- **A bookmark tree is the publisher's CLAIM about its own structure**, not a
  measurement of the document. A PDF with a stale, incomplete or wrongly
  pointing tree carries that error straight into the segmentation, and R761
  says nothing about how common that is. One of the eight reference PDFs here
  already carries a tree whose destinations do not resolve.
- **SK2's own figures** (1 967, 163, 794, 180.50 s, 3 253 MiB, 1/6 · 2/6 · 4/6)
  are `vegnormal-okf`'s documentation and stand as premises wherever they were
  not re-measured here. The rows in § 2 were re-measured.
- **The 12-position reference is n = 12**, stratified 8 `pdf`, 3 `docx`,
  1 `xlsx`, so every per-type fraction is a fraction of 8, 3 or 1. Both
  readings of the `xlsx` fasit are reported, never one.
- **"Delivered" is not "answered."** hit@k asks whether the gold concept
  reached the payload, and nothing here evaluates an answer.
- Position 0's `|F|`, the `xlsx` fasit's `|F|`, the `pptx` fasit, re-rating the
  reference positions and routing between bundles on `--id` remain blocked on
  an **operator decision**, not on code. This round moved none of them.