Imagine we need to pass a a number structured objects to the web application - for instance, locale, layout settings and a definition of some query. This can be easily done with JSON or XML similar to the following fragment:

<Locale>en</Locale>  
<Layout>  
  <Block id="header">hide</Block>  
  <Block id="footer">hide</Block>  
  <Block id="navigation">minimize</Block>  
</Layout>  
<Query>  
  <What>water</What>  
  <When>  
    <Start>2010-01-01</Start>  
  </When>  
</Query>

However, passing such structures with HTTP implies (roughly speaking) HTTP POST.

Now assume we're limited to HTTP GET. Is there some kind of a standard solution for encoding structured data in HTTP GET request parameters?

I can easily imagine something like:

Locale=en&
Layout.Block.header=hide&
Layout.Block.footer=hide&
Layout.Block.navigation=minimize&
Query.What=water&
Query.When.Start=2010-01-01

But what I'm looking for is a "standard" syntax, if there's any.

ps. I'm surely aware of the problem with URL length. Please assume that it's not a problem in this case.