openerp reporting syntax
You can iterate on a list generated by a function defined on report's  related .py file.
Just look for examples on the addons, there are plenty of them, like:

account/report/account_aged_partner_balance.rml: 
           [[ repeatIn(get_lines(data['form']), 'partner') ]]
I've been struggling trying to mimic in openerp a report found in Tryton for the module Health GNU. In their report folder lies a report.odt file very similar to any sxw report found in openerp, with a few exceptions that is. For instance, instead of openERP's:  
[[repeatIn(objects,'test')]] 
we have an opening and closing tag of for making the previous exmaple as such:  
<FOR EACH="TEST IN OBJECTS"> .... </FOR> 
How can I mimic the following in a traditional sxw report:  
<for each="case in test.critearea">
<if test="case.excluded==0">  #this is outside the table
...values in table...  #table starts here
</if>
<for>
which basically excludes an entire row when matched.
using familiar syntax such as [[ case.excluded==False ]] didnt work.