Are different translation units allowed to define structures with the same name?

Suppose I have a.c and b.c, which both define types called struct foo, with different definitions:

#include <stdio.h>

struct foo {
    int a;
};

int a_func(void) {
    struct foo f;
    f.a = 4;
    printf("%d\n", f.a);
    return f.a * 3;
}

#include <stdio.h>

struct foo { // same name, different members
    char *p1;
    char *p2;
};

void b_func(void) {
    struct foo f;
    f.p1 = "hello";
    f.p2 = "world";
    printf("%s %s\n", f.p1, f.p2);
}

In C, can these files both be linked together as part of a standards-conforming program?

(In C++, I believe this is forbidden by the One Definition Rule.)

Struct tags are identifiers with no linkage (C11 6.2.2/6)

The rules about multiple definitions of identifiers with no linkage are found in 6.7/3:

If an identifier has no linkage, there shall be no more than one declaration of the identifier (in a declarator or type specifier) with the same scope and in the same name space, except that:

• a typedef name may be redefined to denote the same type as it currently does, provided that type is not a variably modified type;
• tags may be redeclared as specified in 6.7.2.3.

In your program, the two declarations of foo are in different scopes , so the condition "with the same scope" is not satisfied and therefore this rule is not violated.