examples/html-index.qmd

The rendered page

The fixture below is rendered on its own, the way quarto render examples/html-index.qmd --to html renders it. This page frames that output rather than reproducing it.
The source

---
title: "quarto-index HTML index probe"
from: markdown-smart
filters:
  - index
---

# Cross-references that repeat, and ones that only look alike

Properties of the generated HTML index that the LaTeX back-end has no
equivalent of, so they cannot be probed through a `.tex` render.

The entry those targets can name: [ab]{.index entry="A!B"}.

One target repeated on one key is one cross-reference, not two — the reader
wants the target, not a count of how the marks were spread:
[zeta]{.index see="A!B"} and again [zeta]{.index see="A!B"}.

Two targets on one key that print identically but name different things — a
two-level target, and a single level that merely contains the level join —
are two cross-references. Only the two-level one names an entry that exists,
so only it is a link:
[eta]{.index see="A!B"} and [eta]{.index see="A: B"}.

# Ids the author has already used

An id the extension would otherwise mint for itself, written by the author on
a mark of their own: [theta]{#qi-mark-1 .index}. An id can also sit where the
document tree carries no id at all — written inside raw HTML, which only a
reading of the raw text itself can see:

```{=html}
<p Id="qi-mark-3"></p>
```

The marks that follow must be given neither id — two elements answering to
one name send one of the two locators to the wrong place: [iota]{.index} and
[kappa]{.index}.

The same for an entry id: [lambda]{#qi-entry-1 .index}.

A span forging this extension's own plumbing attribute must not steal a real
mark's anchor: [decoy]{data-qi-pending="1"} is not a mark at all, and
[nu]{.index see="A!B" data-qi-pending="2"} is a cross-reference, which never
carries an anchor of its own.

# Entries whose sort keys are equal

Two terms differing only in ASCII case fold to the same sort key, so the tie
falls to character code and the capital comes first. They are written here in
the opposite order to the one they must appear in, so the index cannot be
right by having left them alone: [bee]{.index} and [Bee]{.index}.