### Discussed in https://github.com/quarto-dev/quarto-cli/discussions/5873

<div type='discussions-op-text'>

<sup>Originally posted by **dense-set** June 11, 2023</sup>
### Description

(Not sure if this is a (even a?) bug of Quarto or something else, hence asking in Q&A.)

I am learning to use Quarto. Playing around, I discovered that passing wrong arguments to the header YAML sometimes gets undetected and the file still renders. For instance, with `highlight-style: bad123`, the following still renders:

````qmd
---
title: test
highlight-style: bad123
jupyter: python3
---

```{python}
import numpy as np

a = np.arange(15).reshape(3, 5)
a.shape
```
````

However, if I mess up the argument of `jupyter`, I get greeted with an error.

Why is so? Is this expected behaviour?</div>
cscheid
2023-06-11T20:42:38Z
mcanouil
yaml-validation
closed
No yaml validation for `highlight-style`
https://github.com/quarto-dev/quarto-cli/issues/5881