diff --git a/lib/romlib/jmptbl.i b/lib/romlib/jmptbl.i
index 338cd8a..5e33e0e 100644
--- a/lib/romlib/jmptbl.i
+++ b/lib/romlib/jmptbl.i
@@ -3,6 +3,10 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
+# Format:
+# index	lib	function	[patch]
+# Add "patch" at the end of the line to patch a function. For example:
+# 14	mbedtls	mbedtls_memory_buffer_alloc_init	patch
 
 0	rom	rom_lib_init
 1	fdt	fdt_getprop_namelen
@@ -32,4 +36,4 @@
 25	mbedtls	mbedtls_x509_get_sig_alg
 26	mbedtls	mbedtls_md_info_from_type
 27	c	exit
-28	c	atexit
+28	c	atexit
\ No newline at end of file