Retrieving default values in XML tree hierarchy

[nightcor3]

Is it possible to set and retrieve default values in an XML hierarchy. \[code\] <commission-rate> <region-NA> <!-- can we set a default at this level, if userId is NOT 123, it should return this default --> <userId-123> 9 </userId-123> </region-NA> </commission-rate>\[/code\]For example, if I want to retrieve commission-rate.region-NA, it should return the default (say 5), but commission-rate.region-NA.userId-123 should pull 9 as the value.Also, is using XML tags like this recommended or I should be using named attributes (e.g. Thanks in advance.