Index: src/OFOnce.h
==================================================================
--- src/OFOnce.h
+++ src/OFOnce.h
@@ -30,9 +30,17 @@
 #endif
 
 #ifdef __cplusplus
 extern "C" {
 #endif
-extern void OFOnce(OFOnceControl *control, void (*func)(void));
+/**
+ * @brief Executes the specified function exactly once in the application's
+ *	  lifetime, even in a multi-threaded environment.
+ *
+ * @param control An OFOnceControl. This should be a static variable
+ *		  preinitialized to `OFOnceControlInitValue`.
+ * @param function The function to execute once
+ */
+extern void OFOnce(OFOnceControl *control, void (*function)(void));
 #ifdef __cplusplus
 }
 #endif

Index: src/OFOnce.m
==================================================================
--- src/OFOnce.m
+++ src/OFOnce.m
@@ -26,26 +26,26 @@
 #ifdef OF_AMIGAOS
 # include <proto/exec.h>
 #endif
 
 void
-OFOnce(OFOnceControl *control, void (*func)(void))
+OFOnce(OFOnceControl *control, void (*function)(void))
 {
 #if !defined(OF_HAVE_THREADS)
 	if (*control == 0) {
-		func();
+		function();
 		*control = 1;
 	}
 #elif defined(OF_HAVE_PTHREADS)
-	pthread_once(control, func);
+	pthread_once(control, function);
 #elif defined(OF_HAVE_ATOMIC_OPS)
 	/* Avoid atomic operations in case it's already done. */
 	if (*control == 2)
 		return;
 
 	if (OFAtomicIntCompareAndSwap(control, 0, 1)) {
-		func();
+		function();
 
 		OFMemoryBarrier();
 
 		OFAtomicIntIncrease(control);
 	} else
@@ -73,12 +73,12 @@
 	}
 
 	Permit();
 
 	if (run) {
-		func();
+		function();
 		*control = 2;
 	}
 #else
 # error No OFOnce available
 #endif
 }