[Jelly] undefined tag is just ignored

[T. H. Lin]

<jelly:jelly xmlns="myns">
   <a>
      <b ... />
   </a>
   <a />
</jelly:jelly>

I only define tag <b> in namespace "myns"
<a> is not defined

The Jelly will run <b .. /> TagScript
and put <a></a><a></a> in outout.

is this as expected?

thanks very much :-)