diff --git a/src/script/api/script_signlist.hpp b/src/script/api/script_signlist.hpp
--- a/src/script/api/script_signlist.hpp
+++ b/src/script/api/script_signlist.hpp
@@ -19,7 +19,29 @@
  */
 class ScriptSignList : public ScriptList {
 public:
+#ifdef DOXYGEN_API
 	ScriptSignList();
+
+	/**
+	 * Apply a filter when building the list.
+	 * @param filter_function The function which will be doing the filtering.
+	 * @param params The params to give to the filters (minus the first param,
+	 *  which is always the index-value).
+	 * @note You can write your own filters and use them. Just remember that
+	 *  the first parameter should be the index-value, and it should return
+	 *  a bool.
+	 * @note Example:
+	 *  function Contains(sign_id, str)
+	 *  {
+	 *    local name = ScriptSign.GetName(sign_id);
+	 *    return name != null && name.find(str) != null;
+	 *  }
+	 *  ScriptSignList(Contains, "something");
+	 */
+	ScriptSignList(void *filter_function, int params, ...);
+#else
+	ScriptSignList(HSQUIRRELVM);
+#endif /* DOXYGEN_API */
 };
 
 #endif /* SCRIPT_SIGNLIST_HPP */