Region blocks do not directly have a visual representation.
They just group a range of lines.
You can use region blocks to enter [[attributes|00001007050000]] that apply only to this range of lines.
One example is to enter a multi-line warning that should be visible.

This kind of line-range block begins with at least three colon characters (""'':''"", U+003A) at the first position of a line[^Since a [[description text|00001007030100]] only use exactly one colon character at the first position of a line, there is no possible ambiguity between these elements.].
You can add some [[attributes|00001007050000]] on the beginning line of a region block, following the initiating characters.
The region block does not support the default attribute, but it supports the generic attribute.
Some generic attributes, like ``=note``, ``=warning`` will be rendered special.
All other generic attributes are used as a CSS class definition.
Attributes are interpreted on HTML rendering.
Any other character in this line will be ignored.

Text following the beginning line will be interpreted, until a line begins with at least the same number of the same characters given at the beginning line.
This allows to enter a region block within a region block.
At the ending line, you can enter some [[inline elements|00001007040000]] after the colon characters.
These will be interpreted as some attribution text.

For example:

```zmk
::::{style=color:green}
A region block with
 an embedded region block
:::{style=color:black}
Embedded
  region
block
::: Embedded Author
:::: Region Author
```
will be rendered in HTML as:
:::::example
::::{style=color:green}
A region block with
 an embedded region block
:::{style=color:black}
Embedded
  region
block
::: Embedded Author
:::: Region Author
:::::

An example for a warning region block:
```zmk
:::warning
Do not copy from the Internet, know your sponsors.
:::
```
will be rendered as:
::::example
:::warning
Do not copy from the Internet, know your sponsors.
:::
::::

Generic attributes that result in a special HTML rendering are:
* example
* note
* tip
* important
* caution
* warning

All other generic attribute values are rendered as a CSS class:
```zmk
:::abc
def
:::
```
is rendered as
::::example
:::abc
def
:::
::::