# ⚠️ Inline KaTeX/MathJax $...$ inside \[grid\] can leak BBCode when used with \[details\]

**URL:** <https://meta.discourse.org/t/inline-katex-mathjax-inside-grid-can-leak-bbcode-when-used-with-details/372802>\
**Category:** Product Support\
**Tags:** math\
**Created:** [July 3, 2025, 4:22pm UTC](https://meta.discourse.org/t/inline-katex-mathjax-inside-grid-can-leak-bbcode-when-used-with-details/372802 "2025-07-03T16:22:25Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![Ethsim2](https://sea3.discourse-cdn.com/meta/user_avatar/meta.discourse.org/ethsim2/32/522255_2.png) [@Ethsim2](https://meta.discourse.org/u/Ethsim2)\
**Post date:** [July 3, 2025, 5:01pm UTC](https://meta.discourse.org/t/inline-katex-mathjax-inside-grid-can-leak-bbcode-when-used-with-details/372802/2 "2025-07-03T17:01:14Z")

</div>

so i thought i’d Update everything on the admin panel, and set about doing some tests

* * *

```plaintext
[details="deriving the formula for cartesian curl"]
[grid]
$$
\nabla \times \mathbf{A} = \left| \begin{matrix}
\hat{i} & \hat{j} & \hat{k} \\
\partial_x & \partial_y & \partial_z \\
A_x & A_y & A_z
\end{matrix} \right|
$$
$$
\nabla \times \mathbf{A} = \left| \begin{matrix}
\hat{i} & \hat{j} & \hat{k} \\
\partial_x & \partial_y & \partial_z \\
A_x & A_y & A_z
\end{matrix} \right|
$$
[/grid]

[grid]
$$
\begin{align*}
\nabla \times \mathbf{A} =\ 
&\hat{i} \left| \begin{matrix}
\partial_y & \partial_z \\
A_y & A_z
\end{matrix} \right|
- \hat{j} \left| \begin{matrix}
\partial_x & \partial_z \\
A_x & A_z
\end{matrix} \right| \\
&+ \hat{k} \left| \begin{matrix}
\partial_x & \partial_y \\
A_x & A_y
\end{matrix} \right|
\end{align*}
$$

$$
\begin{align*}
\nabla \times \mathbf{A} =\ 
&\hat{i} \left| \begin{matrix}
\partial_y & \partial_z \\
A_y & A_z
\end{matrix} \right|
+ \hat{j} \left| \begin{matrix}
A_z & A_x \\
\partial_z & \partial_x
\end{matrix} \right| \\
&+ \hat{k} \left| \begin{matrix}
\partial_x & \partial_y \\
A_x & A_y
\end{matrix} \right|
\end{align*}
$$
[/grid]
[/details]

```

 ![A vibrant, close-up photograph depicts a red poppy in full bloom, showcasing its delicate, crinkled petals and dark central seed pod against a blurred green background. (Captioned by AI)](https://global.discourse-cdn.com/meta/original/4X/8/d/7/8d7fe08224f7588dffbf39090af73aca1dad25d5.png)

pass ✅

* * *

> **AI being daft by putting excessive whitespace between two $...$ in grid**
>
> ```plaintext
> [details="deriving the formula for cartesian curl"] 
> [grid]
> $\nabla \times \mathbf{A} = \left| \begin{matrix}
> \hat{i} & \hat{j} & \hat{k} \\
> \partial_x & \partial_y & \partial_z \\
> A_x & A_y & A_z
> \end{matrix} \right|$
> 
> $\nabla \times \mathbf{A} = \left| \begin{matrix}
> \hat{i} & \hat{j} & \hat{k} \\
> \partial_x & \partial_y & \partial_z \\
> A_x & A_y & A_z
> \end{matrix} \right|$
> [/grid]
> 
> [grid]
> $\begin{aligned}
> \nabla \times \mathbf{A} =\ 
> &\hat{i} \left| \begin{matrix}
> \partial_y & \partial_z \\
> A_y & A_z
> \end{matrix} \right|
> - \hat{j} \left| \begin{matrix}
> \partial_x & \partial_z \\
> A_x & A_z
> \end{matrix} \right| \\
> &+ \hat{k} \left| \begin{matrix}
> \partial_x & \partial_y \\
> A_x & A_y
> \end{matrix} \right|
> \end{aligned}$
> 
> $\begin{aligned}
> \nabla \times \mathbf{A} =\ 
> &\hat{i} \left| \begin{matrix}
> \partial_y & \partial_z \\
> A_y & A_z
> \end{matrix} \right|
> + \hat{j} \left| \begin{matrix}
> A_z & A_x \\
> \partial_z & \partial_x
> \end{matrix} \right| \\
> &+ \hat{k} \left| \begin{matrix}
> \partial_x & \partial_y \\
> A_x & A_y
> \end{matrix} \right|
> \end{aligned}$
> [/grid]
> [/details]
> 
> ```
> 
> ![A fluffy, white Samoyed dog stands proudly in a snowy landscape, looking directly at the camera with a cheerful expression. (Captioned by AI)](https://global.discourse-cdn.com/meta/original/4X/5/2/a/52ae14fcd353b3c2d98ae82f0bb3163578c76fb0.png)
> 
> fail ❌

* * *

```plaintext
[details="deriving the formula for spherical curl"]

[grid]
$$
\nabla \times \mathbf{A} =
\frac{1}{r^2 \sin\theta}
\left| \begin{matrix}
\hat{r} & r\hat{\theta} & r\sin\theta\,\hat{\phi} \\
\partial_r & \partial_\theta & \partial_\phi \\
A_r & r A_\theta & r\sin\theta\, A_\phi
\end{matrix} \right|
$$

$$
= \frac{1}{r^2 \sin\theta}
\left| \begin{matrix}
\hat{r} & \hat{\theta} & \hat{\phi} \\
\partial_\theta & \partial_\phi & \partial_r \\
r A_\theta & r \sin\theta A_\phi & A_r
\end{matrix} \right|
$$
[/grid]

[grid]
$$
\begin{align*}
= \frac{1}{r^2 \sin\theta} \Big(
&\hat{r} \left| \begin{matrix} \partial_\theta & \partial_\phi \\ r A_\theta & r \sin\theta A_\phi \end{matrix} \right|
\ \\&- \hat{\theta} \left| \begin{matrix} \partial_r & \partial_\phi \\ A_r & r \sin\theta A_\phi \end{matrix} \right| \\
&+ \hat{\phi} \left| \begin{matrix} \partial_r & \partial_\theta \\ A_r & r A_\theta \end{matrix} \right|
\Big)
\end{align*}
$$

$$
\begin{align*}
= \frac{1}{r^2 \sin\theta} \Big(
&\hat{r} \left| \begin{matrix} \partial_\phi & \partial_r \\ r \sin\theta A_\phi & A_r \end{matrix} \right|
\ \\&+ \hat{\theta} \left| \begin{matrix} A_r & r \sin\theta A_\phi \\ \partial_r & \partial_\phi \end{matrix} \right| \\
&+ \hat{\phi} \left| \begin{matrix} \partial_\theta & \partial_r \\ r A_\theta & A_r \end{matrix} \right|
\Big)
\end{align*}
$$
[/grid]

[/details]

```

 ![A fluffy, white dog with floppy ears sits attentively on a patterned rug, looking slightly to the left with a cheerful expression. (Captioned by AI)](https://global.discourse-cdn.com/meta/original/4X/c/b/5/cb5a20ed3ef4632050a020083ef60023c0b5424d.png)

pass ✅

* * *

```plaintext
[details="deriving the formula for spherical curl"]

[grid]
$$
\nabla \times \mathbf{A} =
\frac{1}{r^2 \sin\theta}
\left| \begin{matrix}
\hat{r} & r\hat{\theta} & r\sin\theta\,\hat{\phi} \\
\partial_r & \partial_\theta & \partial_\phi \\
A_r & r A_\theta & r\sin\theta\, A_\phi
\end{matrix} \right|
$$

$$
= \frac{1}{r^2 \sin\theta}
\left| \begin{matrix}
\hat{r} & \hat{\theta} & \hat{\phi} \\
\partial_\theta & \partial_\phi & \partial_r \\
r A_\theta & r \sin\theta A_\phi & A_r
\end{matrix} \right|
$$
[/grid]

[grid]
$\begin{align*}
= \frac{1}{r^2 \sin\theta} \Big(
&\hat{r} \left| \begin{matrix} \partial_\theta & \partial_\phi \\ r A_\theta & r \sin\theta A_\phi \end{matrix} \right|
\ \\&- \hat{\theta} \left| \begin{matrix} \partial_r & \partial_\phi \\ A_r & r \sin\theta A_\phi \end{matrix} \right| \\
&+ \hat{\phi} \left| \begin{matrix} \partial_r & \partial_\theta \\ A_r & r A_\theta \end{matrix} \right|
\Big)
\end{align*}$ $\begin{align*}
= \frac{1}{r^2 \sin\theta} \Big(
&\hat{r} \left| \begin{matrix} \partial_\phi & \partial_r \\ r \sin\theta A_\phi & A_r \end{matrix} \right|
\ \\&+ \hat{\theta} \left| \begin{matrix} A_r & r \sin\theta A_\phi \\ \partial_r & \partial_\phi \end{matrix} \right| \\
&+ \hat{\phi} \left| \begin{matrix} \partial_\theta & \partial_r \\ r A_\theta & A_r \end{matrix} \right|
\Big)
\end{align*}$
[/grid]

[/details]

```

 ![A brightly coloured hot air balloon, adorned with patchwork patterns, floats peacefully against a clear blue sky. (Captioned by AI)](https://global.discourse-cdn.com/meta/original/4X/f/1/6/f1685844896e56aa509c0b4bb40345fb97bb4a85.png)

pass ✅

* * *

```plaintext
[details="deriving the formula for spherical curl"]

[grid]
$$
\nabla \times \mathbf{A} =
\frac{1}{r^2 \sin\theta}
\left| \begin{matrix}
\hat{r} & r\hat{\theta} & r\sin\theta\,\hat{\phi} \\
\partial_r & \partial_\theta & \partial_\phi \\
A_r & r A_\theta & r\sin\theta\, A_\phi
\end{matrix} \right|
$$

$$
= \frac{1}{r^2 \sin\theta}
\left| \begin{matrix}
\hat{r} & \hat{\theta} & \hat{\phi} \\
\partial_\theta & \partial_\phi & \partial_r \\
r A_\theta & r \sin\theta A_\phi & A_r
\end{matrix} \right|
$$
[/grid]

[grid] $\begin{align}
= \frac{1}{r^2 \sin\theta} \Big(
&\hat{r} \left| \begin{matrix} \partial_\theta & \partial_\phi \\ r A_\theta & r \sin\theta A_\phi \end{matrix} \right|
\ \\&- \hat{\theta} \left| \begin{matrix} \partial_r & \partial_\phi \\ A_r & r \sin\theta A_\phi \end{matrix} \right| \\
&+ \hat{\phi} \left| \begin{matrix} \partial_r & \partial_\theta \\ A_r & r A_\theta \end{matrix} \right|
\Big)
\end{align}$ $\begin{align}
= \frac{1}{r^2 \sin\theta} \Big(
&\hat{r} \left| \begin{matrix} \partial_\phi & \partial_r \\ r \sin\theta A_\phi & A_r \end{matrix} \right|
\ \\&+ \hat{\theta} \left| \begin{matrix} A_r & r \sin\theta A_\phi \\ \partial_r & \partial_\phi \end{matrix} \right| \\
&+ \hat{\phi} \left| \begin{matrix} \partial_\theta & \partial_r \\ r A_\theta & A_r \end{matrix} \right|
\Big)
\end{align}$ [/grid]

[/details]

```

that’s where it fails

 ![The image displays a complex mathematical formula and derivation process, likely related to spherical coordinates and vector calculus, presented in a code-like format with various symbols and equations. (Captioned by AI)](https://global.discourse-cdn.com/meta/original/4X/1/4/c/14c710265f41e423bd77009411aab227a7a43522.png)

⚠ the problem is that i’m putting too few whitespace between [grid] → `object` and/or `object` → [/grid]

---

_[View the full topic](https://meta.discourse.org/t/inline-katex-mathjax-inside-grid-can-leak-bbcode-when-used-with-details/372802)._