Differences in add_index_string()

I was creating an array for one of my functions and looked in apidoc.txt (included with RC1) and the file specifies: add_index_string(return_value,index,str) I attempt to use that function and get an error about too few actual parameters. ZEND_API.c defines the function as: add_index_string(zval *arg, uint index, char *str, int duplicate) Is the duplicate variable something that was just added? I understand what's going on, and assume it's just that the docs haven't been updated. The same is in effect for the add_index_stringl() Thanks, Brad