sFlow sample - multiple flow data formats

Hi,

I'm currently developing an sFlow collector and I have a question about
the flow data structure.

There can be multiple flow data entries in one sample but I assume
always only one of each format? Is that defined somewhere? (for v.5)

And the same with the extended data in v.<4? There shouldn't be the same
extended data format more then once, or?

Regards

-- 
Elisa Jasinska
http://www.ams-ix.net