Layout type

This uses a single table to handle all 5 boxes, in the most obvious way. (So it doesn't use the "table trick" to alter the linearisation).

It is very robust. Perhaps the hybrid technique using a table just for the 3-columns, and also using the "table trick", is better. There is a lot to be said for making layout tables 1-dimensional, then nesting them to achieve structure at right angles to this.

Leftbar

First leftbar filler header

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Second leftbar filler header

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Article

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Second article filler header

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Rightbar

Rightbar filler header

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