Gap in Shen Hao lens boards

[cluttered]

I'm looking at buying some Shen Hao lens boards, like the ones in this auction:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=281363938484

But I notice that these particular lens boards have a "gap" or a "notch" at the top of each board. What is this for, and could this cause a light leak on some cameras? For what it's worth, I'd be using them on a Chamonix. Other Linhof-compatible lens boards don't seem to have this gap at the top.

[Lachlan 717]

They're fine to use.

Some cameras had locating pins that require this notch. Your camera should have a circular opening for the rear of the lens; this will be much smaller than the outer size of the lens board, meaning this notch won't allow light ingress.

[cluttered]

That's what I had suspected, thanks for the confirmation :)

[vinny]

Almost all linhof boards will work. The thicker ones won't in my experience.