Markdown Features

What Noteism already supports across block elements, inline formatting, tables, code, math, Mermaid, images, and mixed markdown.

The practical answer

Noteism already covers a lot more than headings and a couple of list bullets. The current editor/parser/render stack handles real CommonMark and GFM-heavy documents with a bunch of specialized surfaces on top.

Block coverage

Block type	Status
Headings `#` to `######`	Implemented
Paragraphs and hard line breaks	Implemented
Nested blockquotes	Implemented
Ordered, unordered, and task lists	Implemented
Definition lists	Implemented
Horizontal rules	Implemented
GitHub-style callouts	Implemented
Fenced code blocks with highlighting	Implemented
Tables with structured editing	Implemented
Display math blocks	Implemented
Mermaid diagram blocks	Implemented
`[TOC]` blocks	Implemented
Footnote references and definitions	Rendered today

Inline coverage

Inline feature	Status
Bold / italic / strikethrough / underline	Implemented
Inline code	Implemented
Highlight `==text==`	Implemented
Clickable links	Implemented
Bare URL and email autolinking	Implemented
Inline math	Implemented
Subscript and superscript	Implemented
Emoji shortcode rendering and autocomplete	Implemented
Mixed and nested inline formatting	Implemented
Backslash escaping	Implemented

Specialized surfaces

Code blocks are not just rendered and abandoned.

click a rendered block to open an inline highlighted editor
keep a dedicated raw-fence edit path when you need the literal markdown
use the hover copy button on rendered blocks
keep syntax highlighting theme-aware in both light and dark themes

Tables get a real editing surface.

floating table toolbar
add/remove rows and columns
alignment controls
tab-to-next-cell flow
source toggle and copy controls
inline markdown rendering inside cells
markdown re-alignment instead of leaving the ASCII structure trashed

Math support includes both inline and display paths.

inline math with live rendered output
display blocks through a LaTeX → MathML pipeline
raw $$...$$ editing on focus
horizontal scrolling for wide formulas
graceful error rendering when the LaTeX is broken

Mermaid support is already production-minded, not a screenshot gimmick.

async Mermaid CLI rendering
disk-backed caching
viewport-aware prioritization
responsive sizing from intrinsic SVG dimensions
contrast hardening for both dark and light themes

Images are handled as first-class markdown blocks.

local image paths
remote HTTP/HTTPS images with caching
width metadata parsing
inline zoom controls that rewrite markdown width settings
rendered alt-text captions

Callout syntax already supported

> [!NOTE]
> This is a note callout.

> [!TIP]
> This is a tip callout.

> [!WARNING]
> This is a warning callout.

Supported callout labels in the current app:

[!NOTE]
[!TIP]
[!IMPORTANT]
[!WARNING]
[!CAUTION]

List behavior worth knowing

Enter continues ordered, unordered, and task lists intelligently
Shift+Tab supports outdent behavior
nested ordered numbering like 2.1 and 1.3.2 is already handled
multi-line list groups stay grouped during editing instead of exploding into nonsense
task list checkboxes remain interactive without forcing accidental edit-mode switches

Mixed markdown is the point

Noteism is designed to survive documents that mix prose, tables, task lists, code, diagrams, quotes, and math in the same file without turning the editor into a clown show.