The tax-basis K-1 shared each entry's built-in gain, property without a basis, prepaid at book and property distributed among the members entry by entry, every tied odd cent to the first member: three equal odd-cent properties contributed 50/50 left the members three cents apart. Apply D-38's rule (the closes' cumulative largest remainder, through kernel::apportion_cumulative): tax_capital::RunningSplit keeps each member's exact running share, rounds the running shares afresh to the cent and hands out the change, so no member's running share is ever a cent from exact and tied cents alternate. A negative running whole is rounded as its magnitude, a zero one by the sign of the whole just split, so a run of losses mirrors its gains part for part. Exact running shares are taken to ten places before rounding: a sum of Decimal thirds can sit a hair under its cent (the law found 399.93 as 399.9299...). tax_capital::entry_parts runs the splits over every posted entry from the books' first, in date order, whatever span is asked for, with one count per set of members with a part in the entry: a member never takes a cent of an entry they had no part in (Item L's capital contributed is the basis of the property that member contributed), and the count never restarts, since its weights are each entry's own amounts, not shares. An entry's reversal takes its original's split back out of the count (RunningSplit::unsplit), so an entry's cents are the same in every span and next year's beginning is this year's ending. The K-1's per-entry lines come from k1::entry_lines, which k1_detail now uses too. The book property each member contributed in an entry stays split entry by entry (each member's property must stay within their own credit); B-36 says so. Tests: tied_odd_cents_of_property_basis_run_cumulatively (fails on the per-entry split: 665.86 / 665.83); a_member_outside_an_entry_never_ takes_its_cents (three members; fails with one count for all members), an_entrys_odd_cent_is_the_same_in_every_span (a reversal across the span's start; fails with the count carried span by span or the reversal not taken out), the_split_runs_in_date_order (fails in posting order); the law a_running_split_never_drifts_a_cent (5,000 cases: the largest-remainder rounding of exact integer shares, ties to the first, and the negated run mirrored; fails with ties to the later member or a zero running whole rounded as a gain); unit tests for one split, alternating ties, a member outside a split, the mirror at zero, unsplit and the thirds case; bookspec example partnership-k1-tax-basis-odd-cents. rules.md B-36, the handbook (tracing figures), STATUS, testing.md and verification.md updated. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01T3gXMVt7XJPi6ens1or9Dj
Specification sources
wanderbooks' rules come from documents, not from anyone's memory. This
directory holds the authorities the engine's specs cite (docs/spec/rules.md
is the rule catalog), and every spec block in the code carries a SOURCE:
line pointing into it.
The authority stack
There is no single "bible" of US bookkeeping. Authority is layered, and the layers differ in what they cover and in whether we may copy them:
| Layer | What it governs | Copyright | Here |
|---|---|---|---|
| Pacioli (1494), Geijsbeek translation (1914) | The mechanics of double entry: debits equal credits, the trial balance, one money, writing only forward, correcting by opposite entry, closing into capital. No modern standard restates these; they predate every regulator. | Public domain | Vendored verbatim: sources/pacioli-1494.md |
| IRS: Internal Revenue Code, Treasury Regulations, publications, form instructions | Records and supporting documents, retention, accounting periods and methods, information returns (1099), capitalization (de minimis, 12-month rule), partners' capital, tax basis of purchased and contributed property (sources/irs-partnership-basis.md), payroll taxes, rounding on returns, return line items for tax categories (sources/irs-tax-lines.md) |
Public domain (17 U.S.C. §105; IRS.gov's content policy) | Vendored verbatim: sources/irs-*.md, sources/us-public-domain-status.md |
| File formats: Intuit (QuickBooks Online bank CSV, QuickBooks Desktop IIF), ECMA-376 Office Open XML, Microsoft Excel limits, Avery label sheets | What ledger-import reads and writes: bank/card CSV layouts and signs, IIF journal entries, how XLSX stores numbers and Excel's 15-digit precision, asset-label sheet geometry (Avery 5160) |
© Intuit Inc.; © Ecma International; © Microsoft; © Avery Products Corporation | Cited with short quotes, URLs, and hashes: sources/intuit-bank-csv.md, sources/intuit-iif.md, sources/xlsx-numbers.md, sources/avery-5160.md |
| FASB Accounting Standards Codification (ASC) | Authoritative US GAAP: cash flows (ASC 230), revenue and principal vs agent (ASC 606), foreign currency (ASC 830), credit losses and aging (ASC 326), property and depreciation (ASC 360) | © Financial Accounting Foundation | Cited by paragraph with short quotes only (in rules.md; the paragraphs read, with where and when, in sources/fasb-asc.md and below) |
| FASB Concepts Statement No. 8, Chapter 4 (2021) | Definitions of the five elements (it replaced Concepts Statement 6) | © Financial Accounting Foundation; non-authoritative | Cited with short quotes only |
| Textbooks (OpenStax Principles of Accounting, Vol. 1) | Conventions no standard states: normal balances, closing-entry mechanics, straight-line depreciation arithmetic | CC BY-NC-SA 4.0 (incompatible with this repo's license) | Cited with short quotes and attribution only |
| Convention or decision | Where no authority speaks: aging bucket edges, cent rounding among members, closed-period locks | — | Stated as CONVENTION or DECISION, with who decided and when |
How to read a SOURCE line
SOURCE: Pacioli ch. 36 (sources/pacioli-1494.md); IRS Pub. 583 (sources/irs-records.md)
SOURCE: ASC 830-20-30-1 (cited, rules.md B-3)
SOURCE: DECISION (the owner, 2026-10-13)
SOURCE: CONVENTION (QuickBooks aging); nearest authority ASC 326-20-55-38 (illustrative)
A rule whose only source is CONVENTION or DECISION is a candidate for a human to confirm or overturn; nothing else is.
Rules added later never lock out older books
When a rule is tightened (a check added to a command), books written
before it must still open. Journal replay and the SQLite cross-check read
history through the engine's replay_* commands, which skip checks added
later; new commands go through the checked ones. Pinned by
books_written_under_older_rules_still_open (ledger-store).
Vendoring rules
- Public-domain texts are copied verbatim (whitespace normalized), each with its URL, retrieval date, and the SHA-256 of the retrieved file, so anyone can check the excerpt against the original.
- Copyrighted sources are cited by paragraph, quoted briefly, never copied.
- When an authority changes (the IRS revises a publication; a statute is amended), add the new text beside the old with its effective date. Rules that depend on dates (1099 thresholds) must say which text applies when.
- Rules that change with the law are registered in
crates/ledger-core/src/rules.rswith the years they are known for and a review date. Past what it knows, the engine refuses rather than guesses; from the review date, the MCP digest and the viewer flag the rule. Whoever updates one (human or agent) vendors the new official text here, extends the rule, and sends the change upstream: a pull request at https://github.com/swaits/wanderbooks (best), or an issue.
Open: sources we could not verify
Read on 2026-10-13 through Deloitte's free DART roadmaps, which reproduce
ASC text: ASC 230-10-45-16 and -28, 326-20-55-37/38, 606-10-25-23, 45-2,
55-37/38, 830-20-30-1. Read directly in the ASC basic view on 2026-10-14
(sources/fasb-asc.md): 360-10-35-4, 340-10-05-2/4/5, 210-10-45-1/2/5,
230-10-45-7/10/12/13/14/15, 606-10-55-36 through 55-38. Read on
2026-10-20 where public sources reproduce the Codification (EY's FRD on
the statement of cash flows, July 2026; FASB ASUs 2016-15 and 2016-18;
Deloitte's public DART Roadmap): ASC 230-10-10-1, 45-1, 45-4, 45-5,
45-8, 45-9, 45-12(c), 45-13(c), 45-14(a), 45-15(a)/(c), 45-16(a)/(b),
45-17, 45-24 to 45-26, 45-28 to 45-31, 50-3 to 50-8, and 830-230-45-1;
each checked again against the same sources in the P3 review (numbers,
pages and wording hold). Open: 105-10-05-1 to 05-3, read only in their
2009 text (ASU 2009-01, and as Wiley GAAP 2020 quotes them); their
current wording is unconfirmed. Also open (P3 surface review, 2026-10-21): ASC 230-10-45-15(f) (debt
issue costs, cited by B-14 rule 11) is in neither list above; ASC
606-10-25-31, 25-32 and 55-20 (B-16's over-time method) are not yet read;
B-15 rule 6 cites ASC 250 with no paragraph; B-17's 606-10-55-39 is in
neither list. Each is to be read in the ASC basic view and listed in
sources/fasb-asc.md before it is relied on further.