Specifies the new base level of the transcluded fragment. The top-level heading will be set to this level and subsections are transformed accordingly.
This modifier allows to render a section with subsections within another page adjusted to the target's heading level.
If the target heading level is set to 2 and the top-level heading is a h1, each heading within the transcluded fragment is incremented by one.
We are referring to the projectdoc Section Macro, not the Confluence Section Macro.
Since version 1.7 (requires Confluence 5.8+) the Target Heading Level may be set to '*'. In this case the level is calculated depending on the location of the macro. If the parent is a section at level X, the target level will be set to X+1.
You typically should not combine a target level of 'blank' with documents using sections (with levels or a '*').
The use of the blank target level may be deprecated in the future.