+/**
+ * Returns true if and only if the given containers holds the mark.
+ *
+ */
+bool con_has_mark(Con *con, const char *mark);
+
+/**
+ * Toggles the mark on a container.
+ * If the container already has this mark, the mark is removed.
+ * Otherwise, the mark is assigned to the container.
+ *
+ */
+void con_mark_toggle(Con *con, const char *mark, mark_mode_t mode);
+
+/**
+ * Assigns a mark to the container.
+ *
+ */
+void con_mark(Con *con, const char *mark, mark_mode_t mode);
+
+/**
+ * Removes marks from containers.
+ * If con is NULL, all containers are considered.
+ * If name is NULL, this removes all existing marks.
+ * Otherwise, it will only remove the given mark (if it is present).
+ *
+ */
+void con_unmark(Con *con, const char *name);
+