# Transliteration and the fold

The Roman reading aid beside every line, what it is and is not, and the phonetic fold that lets a seeker type a Gurmukhi word the way they hear it and still find it.

- Page: <https://docs.gurbanisoul.com/scripture/transliteration-and-the-fold/>
- Updated: 2026-09-27
- Verified against: `6332e94` on 2026-09-25
- From the Sri Guru Granth Sahib Ji — Knowledge Base wiki. Sri Guru Granth Sahib Ji is quoted verbatim, cited by Ang, and never altered.

---

> **Explanation, not scripture — scholar review pending.** These pages explain the
> scripture to engineers and students. Every quoted line is verbatim from the pinned database and
> cited by Ang; everything else is explanation, written by engineers and awaiting a Granthi's
> review. Where this page and the scripture differ, the scripture is right.

Beside every line the database keeps a **transliteration** — the line in Roman
letters, built by the pipeline from the Gurmukhi:

> ੴ ਸਤਿ ਨਾਮੁ ਕਰਤਾ ਪੁਰਖੁ ਨਿਰਭਉ ਨਿਰਵੈਰੁ ਅਕਾਲ ਮੂਰਤਿ ਅਜੂਨੀ ਸੈਭੰ ਗੁਰ ਪ੍ਰਸਾਦਿ ॥  
> *ik oankaar sat naam karataa purakh nirabhau niravair akaal moorat ajoonee saibhn gur prasaad*  
> — Sri Guru Granth Sahib Ji · Ang 1

It is a reading aid for people who do not read Gurmukhi, and a search key. It is **not** scripture:
it is never cited, never verified, never shown alone. Several Roman schemes exist and none is
canonical; the pipeline's is consistent, and that consistency is what search needs.

## What the fold is for

Seekers type a Gurmukhi word the way they hear it: *waheguru*, *vaahiguroo*, *wahegurooh*. A search
that demanded the pipeline's exact spelling would miss most of them. The **fold** — `roman_norm` —
reduces every spelling of a word to one key by five rules (letter substitutions, digraphs, voicing
pairs, the y glide, vowels dropped and doubles collapsed), so *waheguru* and *vaahiguroo* both
become `vhgr`. The database stores the folded form of every line's transliteration
(`translit_norm`), and the query is folded the same way at search time.

The fold is deliberately lossy: it trades precision for recall, which is why the
[search waterfall](https://docs.gurbanisoul.com/architecture/search-waterfall/) tries it only after the exact tiers, and
why the [verification engine](https://docs.gurbanisoul.com/search/verification-engine/) uses it to *find candidates* but
scores them with the full transliteration before deciding a verdict.

## One function, three homes

The same fold must run wherever a key is made: in sggs-data when the database is built, in the
platform at query time, in the app on the device. Three copies, held byte-identical by 24,719
golden vectors — the whole story, with the function read from the source, is
[The Roman fold](https://docs.gurbanisoul.com/search/the-roman-fold/).

## What to remember

- Show the transliteration *under* the Gurmukhi and in a lighter style; never in place of it.
- Never cite a transliteration; cite the Gurmukhi line by Ang.
- Never "improve" the transliteration scheme in one place: it is an index, and a change is a
  coordinated dataset release.
- A seeker's misspelling is the fold's job, not the reader's: the first-letters and skeleton tiers
  exist for the same reason.

Read next: [The Answer Protocol for engineers](https://docs.gurbanisoul.com/scripture/answer-protocol-for-engineers/).