How-to add Octicons in toctree directive?

[kdeldycke]

The root of my Sphinx documentation is a index.md file containing a toctree directive. Nothing special in that and everyone does it.

Being written in the MyST dialect, my toctree looks like that:

```{toctree}
---
caption: Development
maxdepth: 2
hidden:
---
API <click_extra>
tests
genindex
modindex
changelog
todolist
code-of-conduct
license
GitHub repository <https://github.com/kdeldycke/click-extra>
Funding <https://github.com/sponsors/kdeldycke>
```

Now I would like to prefix each entry with an icon of my choice.

My intuition was to do something like that (based on sphinx-design documentation):

```{toctree}
...
:octicon:`checkbox` genindex
...
```

Or:

```{toctree}
...
{octicon}`checkbox` genindex
...
```

But none works. Worse: the entry gets hidden if I prefix it with :octicon: or {octicon}.

How can I do that? Is it a case supported by Furo?

Working case

Note that icons in titles are properly rendered as such in the index, as pointed out previously in #910:

# {octicon}`shield-check` CLI testing

...

Renders to:

[kdeldycke]

For reference, this behavior has been produced with these versions:

 + accessible-pygments==0.0.5
 + alabaster==1.0.0
 + babel==2.17.0
 + beautifulsoup4==4.14.3
 + boltons==25.0.0
 + bracex==2.6
 + certifi==2025.11.12
 + charset-normalizer==3.4.4
 + click==8.3.1
 + click-extra==7.4.0
 + cloup==3.0.8
 + deepmerge==2.0
 + docutils==0.21.2
 + furo==2025.12.19
 + idna==3.11
 + imagesize==1.4.1
 + jinja2==3.1.6
 + markdown-it-py==3.0.0
 + markupsafe==3.0.3
 + mdit-py-plugins==0.5.0
 + mdurl==0.1.2
 + myst-parser==4.0.1
 + packaging==25.0
 + pygments==2.19.2
 + pygments-ansi-color==0.3.0
 + pyyaml==6.0.3
 + requests==2.32.5
 + roman-numerals==4.1.0
 + roman-numerals-py==4.1.0
 + snowballstemmer==3.0.1
 + soupsieve==2.8.1
 + sphinx==8.2.3
 + sphinx-autodoc-typehints==3.5.2
 + sphinx-basic-ng==1.0.0b2
 + sphinx-copybutton==0.5.2
 + sphinx-design==0.6.1
 + sphinx-issues==5.0.1
 + sphinxcontrib-applehelp==2.0.0
 + sphinxcontrib-devhelp==2.0.0
 + sphinxcontrib-htmlhelp==2.1.0
 + sphinxcontrib-jsmath==1.0.1
 + sphinxcontrib-mermaid==1.2.3
 + sphinxcontrib-qthelp==2.0.0
 + sphinxcontrib-serializinghtml==2.0.0
 + sphinxext-opengraph==0.13.0
 + tabulate==0.9.0
 + typing-extensions==4.15.0
 + urllib3==2.6.2
 + wcmatch==10.1
 + wcwidth==0.2.14

[kdeldycke]

Couldn't find a way to do it cleanly so in the mean time I just hard-coded these icons and style with custom CSS: kdeldycke/click-extra@65ad0de

[webknjaz]

Tip

FYI, Pradyun's away for a while — don't expect a response until March.