Just as you can export functions, you can also export variables. When exporting variables, one should only consider the names of the variables. To declare a variable that should be used by a C program, one declares it with the cvar modifier:
Var MyVar : MyTpe; cvar;
This will tell the compiler that the assembler name of the variable (as used by C programs) should be exactly as specified in the declaration, i.e., case-sensitive.
It is not allowed to declare multiple variables as cvar in one statement, i.e. the following code will produce an error:
var Z1,Z2 : longint;cvar;