BISAC Categorizer

BISAC (Book Industry Standards and Communications) subject codes are the book industry's category vocabulary. This skill turns a book's actual content into one primary code plus up to two secondary codes, written into sale.md section 3.

1. Why BISAC Matters on Google Play Books

Official rules from the Google Play Books Partner Center:

• A book requires at least one genre to be published.
• Google recommends BISAC because "genres in the Play Store are based on BISAC"; other standards are auto-mapped to their BISAC equivalent.
• Maximum 3 genres per book, the first one must be the most relevant, and all genres must come from the same subject standard.
• All genres should be from the same subject standard — do not mix BISAC with BIC/CLIL/etc.

Because only three slots exist, the ranking matters as much as the choice.

2. The Selection Procedure

1. Summarize the book in one sentence
        ↓
2. Pick the BISAC section that matches the CONTENT (not the audience)
        ↓
3. Walk down to the most specific leaf heading that is still true
        ↓
4. Primary = the most relevant leaf; Secondary = up to 2 distinct angles
        ↓
5. Verify every code character-for-character at bisg.org
        ↓
6. Write the result into sale.md section 3

Decision rules

1. Content, not reader. A book for managers about writing docs is still COMPUTERS if the subject is documentation tooling.
2. Specific beats general. Choose COM085000 COMPUTERS / Documentation & Technical Writing over COM000000 COMPUTERS / General whenever the specific leaf is true — "General" is a fallback, never a first choice.
3. No duplicates of the same angle. Three codes from the same branch waste slots; secondary codes should cover genuinely different facets (e.g. tools vs. writing craft vs. workflows).
4. Stay inside one subject standard. All codes must be from the same standard (for this project: BISAC).
5. Never invent a code. If no leaf fits, use the closest true heading — BISG's own guidance is "use whatever codes currently best represent your book" — and say so in the note.
6. Verify before writing. Codes change between BISAC editions; confirm each code + heading pair at bisg.org or in references/verified-codes.md (a project-curated subset, verified 2026-10-26).

3. Where Codes Come From

Copyright note: the full BISAC list is © Book Industry Study Group and may not be redistributed. Copy only the few code/heading pairs the book actually uses into sale.md; never dump whole sections into project files.

4. Output Format

Write into sale.md → ## 3. แนะนำหมวดหนังสือ BISAC (...), following the existing structure:

* **หมวดหลัก (Primary BISAC Code):**
* **<CODE>** — `<SECTION> / <Subsection> / <Leaf>` (<คำอธิบายไทย>)

* **หมวดรองที่เกี่ยวข้อง (Secondary BISAC Codes - ถ้าแพลตฟอร์มรองรับ):**
* **<CODE>** — `<SECTION> / <Subsection> / <Leaf>` (<คำอธิบายไทย>)
* **<CODE>** — `<SECTION> / <Subsection> / <Leaf>` (<คำอธิบายไทย>)

Rules for the block:

• Code in bold, heading copied exactly as BISG writes it (English, including slashes and capitalization), followed by a short Thai gloss.
• Primary first; secondaries ordered by relevance.
• If a platform only accepts one code, the primary alone must still stand on its own.

5. Common Mistakes

6. Final QA

• At least one code (Google requires a genre) and at most three
• Primary is the single most relevant heading
• All codes verified character-for-character against bisg.org
• All codes from the same subject standard (BISAC)
• English heading copied exactly; Thai gloss present
• sale.md section 3 updated; sections 1, 2, 4 untouched
• No bulk reproduction of the copyrighted BISAC list