Most AI-generated UIs are visually distinct but structurally identical: hero → three features → CTA → footer. Same heading positions, same column counts, same component vocabulary. **Structural sameness is the AI fingerprint, not visual sameness.** Hallmark's job is to break it.
This file catalogues the **primitive axes** of structural variety. For most builds you should NOT compose a fingerprint axis-by-axis from this file — instead pick a named whole-page shape from [`macrostructures.md`](macrostructures.md), which is faster and prevents default-attractor sameness. Use this file when you need to deviate from a macrostructure's defaults on one or two axes, or when you're auditing an existing page and need vocabulary for what you see.
The axes below are still the building blocks. Pick one option from each to form a *structural fingerprint*. Two pages should never share the same fingerprint.
| **Left-margin** | ⚠️ **Opt-in only — never default.** Eyebrow / number / label in a narrow left column with heading + body to the right. Reads as a templated-editorial AI tell when applied to SaaS / dev-tool / consumer pages. Permitted ONLY when the user explicitly asks for an editorial / specimen layout AND no eyebrow is paired with the heading (label may sit beside body copy; heading must stay in its own row above). The eyebrow-left / heading-right variant is banned outright by slop-test gate 66. | The New York Times Magazine; our Specimen theme — when the user explicitly requests that voice. |
| **Hanging** | Heading floats in negative space *above* the section, with generous breathing room. | David Airey's portfolio; minimal modernist. |
| **Centered display** | Heading dominates centre stage, symmetrical. Formal, welcoming, can feel static if used everywhere. | Apple product pages; Atelier-style runway invitations. |
| **Bottom-aligned** | Heading anchors the *base* of a section, content flows above. Inverts hierarchy. | Swiss editorial; Newsprint masthead-below pattern. |
| **Numbered display** | ⚠️ **Opt-in only — never default.** "01." with a rule line and the heading right beside it. Procedural, sequenced. Banned for default SaaS / consumer / dev-tool pages by slop-test gate 66 (the tag-beside-heading pattern is a templated tell). Permitted only when the user explicitly asks for ordinal / chaptered numbering AND the macrostructure is Long Document, Manifesto, or Catalogue numbered. Even then, prefer the stacked variant: number on its own line above the heading. | Rauno Freiberg's portfolio — when the user explicitly invokes that voice. |
| **Full-bleed with margin reset** | Body at 65ch, but pull-quotes or images bleed full-viewport. Emphasis via scale change. | Medium pull-quotes; Manifesto sections. |
- **Typewriter.** Character-by-character; honest about the medium. Terminal only. **Decorative-graphics constraint:** Terminal output must NOT include standalone scanlines, detached blinking cursors, or random ASCII art. The terminal cursor (`▮`) is allowed only when it sits *inside* a typed command (install code block, N8 Terminal command nav) and signals an honest "you'd type next" affordance. A floating cursor in a hero corner is set decoration; remove it. See [`microinteractions.md`](microinteractions.md) Caret blink row.
- **None.** Everything is just there at load. Some sites should not move. Pentagram, brutalist sites.
## Picking a fingerprint
A fingerprint = one choice per axis. There are 8 × 7 × 5 × 5 × 5 × 6 = **42 000** fingerprints. You will never run out.
Two rules govern choices:
1.**Coherence.** A Newsprint page with multi-column justified body should have a typographic CTA, not an oversized solid button — those don't share a voice. Pick choices that belong to the same *world*.
2.**Anti-repetition.** Across consecutive pages built in the same session, no two should share more than three of the six axes. If the previous page used left-margin headings + single column + hairline divider + outlined button, this page should differ on at least three of those.
Each Hallmark theme has a default structural fingerprint. Use them as starting points only when the brief specifies a theme. **For most builds, pick a macrostructure from [`macrostructures.md`](macrostructures.md) instead** — themes describe *visual surface*, macrostructures describe *page shape*; the latter drives variety more.
The table below is alphabetical by theme to neutralise any "first row = default" attractor. No theme is the default. The **Nav** and **Footer** columns name the default archetype from [`component-cookbook.md`](component-cookbook.md); the routing tables in that file list the acceptable alternates.
If the brief doesn't suggest a fingerprint and the user hasn't picked a theme, **do not default**. Read the brief for a domain word (audio, commerce, docs, agency, restaurant, fashion, fintech, personal, …) and offer the user **three macrostructures from categorically different groups *that fit that domain***. Then let them pick.
The point of three is contrast: a grid-led shape, a document-led shape, a poster-led shape. Picking from categorically different groups is what produces variety; offering three near-twins is the AI tell this whole skill exists to defeat.
**Note on splits.** Some domains split on intent. *Developer-tool docs* and *developer-tool marketing* both have "developer" in them, but the docs page wants a Workbench walkthrough; the marketing page wants Bento Grid + Stat-Led so the SRE can read the value prop in 30 seconds. Same for *personal*: a one-pager about-me and a multi-project portfolio of case studies are *different briefs* — the one-pager wants prose (Long Doc / Letter); the portfolio wants Portfolio Grid / Split Studio. If the brief is ambiguous, **ask one question** to disambiguate ("docs walkthrough or marketing landing?", "one-pager or case studies?") before picking the trio.
If the user shrugs and says "you pick", read the project's CSS for a `/* Hallmark · macrostructure: ... */` stamp; whichever of the trio is most categorically distant from the stamped family is the right pick. Two consecutive outputs should never be from the same family — never two editorial macrostructures, never two grid-led macrostructures.
If the user answers a vague tone word ("modern", "clean", "professional"), that is not a feeling. Re-ask with the domain trio.
The fallback row at the bottom of the table is the *last* resort — only if no domain words appear and the user genuinely cannot pick. In practice, almost every brief contains a domain word; using the fallback usually means you didn't read carefully enough.
