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§10.3.1

Ids and Labels

A field number—part of the label or its own identifier?

✅ NormativeSettled. The requirement holds as written.📄 Page ruleCan be applied from the page alone.Read §10.3.1 in the RFC ↗

The requirement

A field's id is its printed designator, written exactly as printed in escaped brackets outside the bold label. Its label is the printed caption, verbatim. A label MUST NOT repeat the id, and a caption MUST NOT be written as an id.

The distinction

An id is a short printed designator that indexes into the form — 1a, e, H1, Part III. It is what a reader cites when they say "see line 12a".

A label is the caption. A caption is never an id. On a 1099, only the numbered boxes have ids; PAYER'S TIN is a label with no id.

✅  - \[1a\] **Total amount**: 4,200
❌  - **1a Total amount**: 4,200      ← id folded into the label
❌  - \[PAYER'S TIN\] **...**          ← a caption is not an id

Nothing is cleaned up

A label MUST keep its abbreviations, capitalisation and punctuation exactly as printed. A label MUST NOT be renamed, expanded or tidied: FAX (A/C, No) stays FAX (A/C, No).

Implicit numbers

When a printed id carries an implicit number, the id MUST include it.

form-implicit-ids.png
Source: IRS Form 1040 (2020), Refund section, lines 35a–35d (public domain)

A block printed 35a then b, c, d has the ids 35a, 35b, 35c, 35d — not 35a, b, c, d. The 35 is implied by position and is part of how the field is cited; dropping it makes three of the four ids unusable for reference.

Escaping

\[x\] is a printed id "x"; [x] is a checked box. The escape is what keeps them apart — see The Key-Value List (§10.3.2).

More

Sample sources1

Public-domain U.S. federal government source material.

  • IRS Form 1040 (2020), Refund section, lines 35a–35d

Rule id forms-ids-and-labels · forms