The markdown preview doesn't render callouts

[AlessandroTambellini]

Type: Bug

1. Write a callout in a .md file.
   e.g.

> [!WARNING]
> Your message here.

2. Open the preview

Actual: it's rendered as text just without the '>'
Expected: callout rendered

VS Code version: Code 1.98.2 (ddc367e, 2025-03-12T13:32:45.399Z)
OS version: Linux x64 6.13.8-200.fc41.x86_64
Modes:

System Info

Item	Value
CPUs	13th Gen Intel(R) Core(TM) i5-1335U (12 x 3404)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: enabled_on direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_graphite: disabled_off video_decode: enabled video_encode: disabled_software vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: disabled_off webnn: disabled_off
Load (avg)	0, 0, 0
Memory (System)	15.28GB (10.12GB free)
Process Argv	ray-tracing/ --crash-reporter-id 895ca69e-282d-4f6d-86b3-2b9a66e87e1f
Screen Reader	no
VM	0%
DESKTOP_SESSION	gnome
XDG_CURRENT_DESKTOP	GNOME
XDG_SESSION_DESKTOP	gnome
XDG_SESSION_TYPE	wayland

Extensions (13)

Extension	Author (truncated)	Version
copilot	Git	1.293.0
copilot-chat	Git	0.25.1
remotehub	Git	0.64.0
debug-tracker-vscode	mcu	0.0.15
memory-view	mcu	0.0.25
theme-monokai-pro-vscode	mon	2.0.6
debugpy	ms-	2025.4.1
python	ms-	2025.2.0
vscode-pylance	ms-	2025.3.2
cpptools	ms-	1.23.6
cpptools-extension-pack	ms-	1.3.1
remote-repositories	ms-	0.42.0
pdf	tom	1.2.2

A/B Experiments

vsliv368:30146709
vspor879:30202332
vspor708:30202333
vspor363:30204092
vscod805:30301674
binariesv615:30325510
py29gd2263:31024239
c4g48928:30535728
azure-dev_surveyone:30548225
962ge761:30959799
h48ei257:31000450
pythontbext0:30879054
cppperfnew:31000557
dwnewjupyter:31046869
nativerepl2:31139839
pythonrstrctxt:31112756
nativeloc1:31192215
iacca1:31171482
5fd0e150:31155592
dwcopilot:31170013
bajee813:31263137
6074i472:31201624
dwoutputs:31242946
customenabled:31248079
9064b325:31222308
copilot_t_ci:31222730
f27dg485:31264363
e5gg6876:31271075
jda6j935:31233686
pythoneinst12cf:31262606
bgtreat:31268568
fh1c7952:31258891
4gafe986:31271826
31787653:31262186
3e8i5726:31271747
49da9784:31264548

[mjbvz]

Our built-in Markdown support targets common mark. Callouts are not part of the standard markdown syntax

Support for them can be added by extensions such as https://marketplace.visualstudio.com/items?itemName=yahyabatulu.vscode-markdown-alert