Constraints on Nested Tags in Launch Files

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What kinds of tag nesting are allowed in ROS launch files?

For instance, I know I can have global params within the <launch> tag as well as node params within a specific <node> tag.

But can other things be nested inside of the <node> tag, such as <rosparam>, <include>, other <node> tags?

Example 1:

<node>
    <rosparam ... some-file.yml />
</node>

Example 2:

<node>
    <include ... />
</node>

Example 3:

<node>
    <node ... >
        ...
    </node>
</node>

It seems like example 3 would be illegal, but I am unsure about example 1 and 2. Any help is appreciated.