i18n:name - How do I use it

Hi.

I have a template containing 

<p i18n:translate="">First we want to test 
<span style="font-style: italic;" i18n:name="names">names</span>.</p>

If I apply i18nfool-extract, I get 

msgid "First we want to test ${names}."
msgstr "First we want to test ${names}."

and manually add

msgid "names"
msgstr "names"

Then I i18fool-update and edit the pot-File for de_DE to

msgid "First we want to test ${names}."
msgstr "Zuerst wollen wir ${names} testen."

msgid "names"
msgstr "Namen"

However after processing this with Petal I get

<p>Zuerst wollen wir <span style="font-style: italic;">names</span>
testen.</p>

So names is not translated. How do I handle this, or is this a bug (in
2.18).

Sincerely,
Joachim