What's the purpose of these "indents" in the chassis rail?

[disco_monkey79 29]

Having removed the inner and outer lower valance I can get a good look at these indents/cut-outs in the chassis rail. 

 

Are they to ventilate, so any moisture in the chassis rails gets blown out by air being forced through when driving? 

 

Thanks 

[sheffieldcortinacentre 741]

Possible, may also be part of crumple zone like the ones along each side of bonnet.

Or like the round ones in floorpan for locating on the welding jigs.

[disco_monkey79 29]

Great, thanks. I was looking and suddenly couldn't work out if I had seen them before or was imagining it