The structure is essentially identical to a Markdown list, with indentation forming all the logic:
mindmap
Middle element
Branch 1
Branch 2
Branch 3
Branch 4
Sub-branch 1
Sub-branch 2
Sub-branch 3
Sub-sub-branch 1
mindmap
Middle element
Branch 1
Branch 2
Branch 3
Branch 4
Sub-branch 1
Sub-branch 2
Sub-branch 3
Sub-sub-branch 1
You can shape each element within the mindmap:
mindmap
Default shape
[square]
(rounded square)
((circle))
))bang((
)cloud(
{{hexagon}}
mindmap
Default shape
[square]
(rounded square)
((circle))
))bang((
)cloud(
{{hexagon}}
Each element can also add custom icons, if using an icon pack like Font Awesome (fa fa-x) or Material Design (mdi mdi-x). These will not work directly on GitHub without additional configuration (including stylesheets).
Additionally, basic Markdown formatting (bold & italic) works within node names:
mindmap
Root
**Bold** text
::icon(fa fa-book)
*Italic* text
::icon(mdi mdi-skull-outline)
mindmap
Root
**Bold** text
::icon(fa fa-book)
*Italic* text
::icon(mdi mdi-skull-outline)