I was wondering whether there is a placeholder for an explanation in the "merge template". The placeholder I think should not have a visible section in the merge box, but rather be a comment that can be read by anyone who wants to follow up the merge request. Would it work if I just place text like this {{merge|GoBoard|*explanation*}}. (I would normally consider this bad style)

If you want to make an explanation that only shows up during page edit and not on the displayed page itself, the comment "%" operator is sufficient to do the job.

Anyway, I modified the Merge Template to accept a second "comment" argument which shows up in the displayed page. This is for consistency with some of the other templates.