SPDX and docbook documentation, how to do properly?

[David Hurka]

> how to add SPDX tags.

Aren’t docbooks just XML files? The reuse tool would add them as XML comment.

Approximately like this:

$ reuse addheader --style xml --copyright ... index.docbook

<!--
SPDX-CopyrightText ...
SPDX-License-Identifier ...
-->
<!DOCTYPE book ...>
<book ...>
    ....
</book>

> predefined docbook tags,

Do you think it is important to not duplicate authors in the license statement 
and in the <bookinfo> section?
I think just duplicating this makes it easier for the reuse tool.