Question about Motherboard supporting Memory

Hi!

I am building my first desktop, and I have been reading threads these several days.
I have a question when I choose my motherboard.
In the specification of motherboard, in the "Memory Standard" column, some motherboards say "DDR3 1600", and some say "DDR3 1600(O.C)/1333". What is the difference? Does the latter one mean I have to overclock to use DDR3 1600, otherwise my DDR3 1600 memory will only work at 1333 frequency?

If I didn't say the question clearly, here are examples of "DDR3 1600" and "DDR3 1600(O.C)/1333":
http://www.newegg.com/Product/Prod [...] 6813130224
http://www.newegg.com/Product/Prod [...] 6813131366

I never overclock but I will learn how to do it.

Thank you very much!