How to avoid submit/decode of sub-region?

[emsa]

If I have something like this:

 <a4j:region id="outer">
 <a4j:region id="inner>
 </a4j:region>
 <a4j:commandButton ... />
 <a4j:region>

is it somehow possible to submit/decode only 'outer' and skip the contents of the 'inner' region?

Thanks,

/Magnus