Qt Help Project XML link

[zither]

Dear all,

Here is part of Qt Help Project file
@<keywords>
<keyword name="foo" id="MyApplication::foo" ref="doc.html#foo"/>
<keyword name="bar" ref="doc.html#bar"/>
<keyword id="MyApplication::foobar" ref="doc.html#foobar"/>
</keywords>@

For third <keyword...>
If 'id' is used, the keyword does not appear in the index and is only accessible via the linksForIdentifier() function of the QtHelpEngineCore.

So, how can I link that from html file?
I try with like this, but it can't work.
@<a href="MyApplication::foobar">Foobar<a>@
How Can I do that to link this?

Thanks