-void bufcat_su(struct html *, const char *,
- const struct roffsu *);
-void buffmt_man(struct html *,
- const char *, const char *);
-void buffmt_includes(struct html *, const char *);
-void buffmt(struct html *, const char *, ...);
+#if __GNUC__ - 0 >= 4
+__attribute__((__format__ (__printf__, 2, 3)))
+#endif
+void bufcat_fmt(struct html *, const char *, ...);