What does the 'where' keyword mean in C?

I stumbled across this C code today. Can anyone tell me what the 'where' keyword means:

*y = sy + exit->y + (where * (entry->y + esy - exit->y));

Edit:

Ah.. my bad. It is just a variable name. VC++ highlighted it as though it 开发者_如何学编程was a keyword though.

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It's just a variable name...

(The where is highlighted as blue here only because C# supports where as a keyword in LINQ.)

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Here is a list of C's keywords. There is no where keyword in C, it's just a variable (or perhaps a macro).