Vietnamese Tech Writing

Vietnamese engineering and product writing (vi-VN)

Vietnamese technical writing fails differently from Vietnamese marketing writing. Marketing copy goes wrong by being too literal. Technical copy goes wrong by being too Vietnamese — translating the English terms that Vietnamese engineers keep in English, and addressing a reader in documents that describe a system.

Both defects are invisible to a non-engineer proofreader and instantly obvious to the team that has to use the document.

Step 1 — Decide what the document is before writing a word

Two decisions follow from the document type, and both are inverted from the landing-page defaults.

| If you are writing | Register | Terms | |---|---|---| | RFC, design doc, postmortem, runbook, spec | impersonal — no bạn at all | Vietnamese leans formal (bộ nhớ đệm, cơ sở dữ liệu) | | README, tutorial, API docs, UI copy, release notes | bạn | Vietnamese for user-facing nouns | | PR description, code review, standup, chat | mình / no address | English terms throughout | | Status page (customer-facing) | quý khách | plain, non-technical |

bạn in an RFC is a defect. Vietnamese has natural impersonal constructions — Hệ thống sẽ tự động retry, Cần cấu hình biến môi trường — and English does not, which is exactly why translated text is full of bạn.

Which document takes which register, and the impersonal constructions that replace bạn: [references/doc-registers.md](references/doc-registers.md). The full pronoun matrix shared with the other Vietnamese skills: [references/register-matrix.md](references/register-matrix.md).

Step 2 — Core rules (non-negotiable, no file hop needed)

1. Keep the English terms English. deploy, commit, merge, bug, server, cache,

deadline, sprint, backlog, pull request. Translating them is the single loudest machine-translation tell. cam kết for commit is the worst offender — it is a real word meaning to pledge.

1. Never translate environment names. production, staging, dev. `triển khai đến sản

xuất` is not a sentence any Vietnamese engineer has written.

1. Identifiers, branch names, and commit subjects are ASCII. No diacritics, ever. The

commit body may be Vietnamese; the subject line may not.

1. Emit NFC Unicode. Precomposed ế (U+1EBF). NFD breaks font rendering, inflates

character counts past platform limits, and defeats search.

1. Vietnamese has no grammatical plural. ICU messages take other only. A one, few,

many or zero branch in a vi file is always a bug. =0 selectors are fine.

1. Pick one tone-mark style per document — kiểu mới (hoà, thuỷ) by default. Neither

style is wrong; mixing them is.

1. Never use an agree/disagree survey scale. Acquiescence bias inflates agreement by

roughly 10 points. Ask about the property itself.

1. Errors say what happened and what to do. Never quý khách in a developer-facing

surface, and never blame the user.

Step 3 — Look up the term before inventing one

The blocklist of calques that mark machine translation, the terms where both an English and a Vietnamese form are live (server/máy chủ, cache/bộ nhớ đệm — pick one and hold it), and the settled Vietnamese for user-facing UI strings:

[references/glossary.md](references/glossary.md) — machine-readable, so every row is a lint rule.

The reasoning behind which words stay English, and the formality axis that decides the borderline cases: [references/code-switching.md](references/code-switching.md).

Step 4 — Handle the i18n hazards

Vietnamese text runs 25–30% longer than English, so fixed-width buttons truncate. Diacritics force SMS into UCS-2, cutting the segment from 160 characters to 70. Users search without diacritics, so matching must be accent-insensitive. Font subsets that drop stacked diacritics (ề, ộ, ữ) break rendering silently.

[references/i18n-hazards.md](references/i18n-hazards.md) — plus [references/locale-formatting.md](references/locale-formatting.md) for numbers, dates and currency, and [references/unicode-and-tone.md](references/unicode-and-tone.md) for NFC, collation, and input methods.

For a starter resource file: [assets/messages.vi.json.template](assets/messages.vi.json.template) — ASCII keys, NFC values, other-only plurals, both registers.

Step 5 — Product and research writing

Release notes are benefit-led and past-tense (Đã sửa lỗi…, Đã thêm…). Agile terms stay English (sprint, backlog, roadmap — lộ trình is also fine). User stories are Là [vai trò], tôi muốn…, never Như một [vai trò].

Surveys are where this skill earns its keep, because a badly worded Vietnamese survey reads fine and returns wrong numbers: [references/survey-design.md](references/survey-design.md).

Step 6 — Check the claims

App-store listings and in-product claims are advertising under Luật Quảng cáo 16/2012/QH13. An unproven tốt nhất or số 1 in a subtitle is a regulated claim, not a tagline.

[references/banned-phrases.md](references/banned-phrases.md) for the genre-specific list, [references/compliance.md](references/compliance.md) for the cross-cutting advertising, consent, and personal-data rules every Vietnamese skill shares.

Step 7 — Validate, fix, then ship

Run the validator immediately after writing. If it reports errors, fix them and run again. Only present the copy once it passes. NFC violations and ICU plural bugs are invisible to reading.

python scripts/validate_copy.py path/to/doc.md --register eng-impersonal
python scripts/validate_copy.py .git/COMMIT_EDITMSG --doctype commit
python scripts/validate_copy.py messages/vi.json --doctype identifier
python scripts/validate_copy.py survey.md --doctype survey

• --register eng-impersonal|eng-readme|saas|re|formal|consult|... enables PRO002.

--list-rules prints every rule this skill can emit.

• --doctype is what turns on the structural rules. They stay silent without it, because

a 30-character limit is right for an app-store subtitle and nonsense for a design doc: commit, branch, identifier, rfc, postmortem, runbook, survey, app-store-title, app-store-subtitle, app-store-short-description, consent.

• Exit 0 = clean or warnings only. Exit 1 = errors that must be fixed.
• --json for machine-readable findings; --strict to fail on warnings too.
• --fix rewrites NFC violations in place; every other rule is a human judgement call.

Check glyph coverage when a specific web font is specified:

python scripts/check_font_coverage.py path/to/copy.md

Step 8 — Learn from the worked pairs, then hand it to a human

Read the bad→good corpus before writing anything long. Each pair names the failure mode it fixes, and the diagnosis generalizes further than the string does.

[references/examples.md](references/examples.md)

Then run the checklist. The linter catches encoding, blocklisted calques, and the doctype-gated structural rules. It cannot tell you whether a new Vietnamese rendering of an English term reads natural, whether a survey item is leading, or whether an error message is actually actionable. Those need a native speaker who ships software: [references/qa-checklist.md](references/qa-checklist.md)

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: trussary
• Source: trussary/vietnamese-language-skill
• License: MIT

Install and usage instructions live in the source repository linked above.