First do the following:
<verbatim>
mkdir test1
cd test1
uuid=`fossil new repos| awk $2}'`
fossil open repos
echo "Baseline is $uuid" > txt
fossil add txt
fossil com --nosign -m "Commit text refer to [$uuid]"
fossil ui
</verbatim>

Now in the browser select the Timeline and click on the UUID of the leave. Now you should be into the VInfo page of the baseline. In the field you see the clickable reference. Now if you hit the <tt>edit</tt> in the field the VEdit page will be load.

Please have a look into the textbox down the page. The previous comment is inserted to be edit by me, but the closing <tt>]</tt> of the UUID in the comment text is lacking.

If I do not append the lacking <tt>]</tt> the reference will not work correctly anymore if I apply my changes.