diff --git a/nm/nm.c b/nm/nm.c
index 67b9fa0..41ee3ca 100644
--- a/nm/nm.c
+++ b/nm/nm.c
@@ -2,6 +2,8 @@
  * nm.c
  *
  * nm clone for PDP10 Elf36 files.
+ * This is essentially a copy of readelf.c, adjusted to
+ * process the symbol table differently.
  */
 #define _GNU_SOURCE	/* for getopt_long() */
 #include <errno.h>