diff --git a/star/cpiohdr.c b/star/cpiohdr.c

index 9c7a774..2785661 100644

--- a/star/cpiohdr.c

+++ b/star/cpiohdr.c

@@ -536,7 +536,9 @@ cpio_checkswab(ptb)

 }

 /*

- * This simple sum is used for the SYSvr4 file content CRC

+ * This simple sum is used for the SYSvr4 file content checksum.  This is

+ * implemented like Sum32 algorithm.

+ *

  * Use Int32_t to implement the same behavior as the AT&T cpio command.

  */

 LOCAL Int32_t

diff --git a/star/star.1 b/star/star.1

index 95b202c..a931a6f 100644

--- a/star/star.1

+++ b/star/star.1

@@ -913,9 +913,9 @@ archive format because of its limited portability.

 .B crc

 This format is similar to the

 .B asc

-cpio format but in addition uses a simple byte based checksum called

+cpio format but in addition uses a simple byte based checksum called here as

 .BR CRC .

-Try to avoid the

+This algorithm is simple Sum32 -- not a polynomial CRC.  Try to avoid the

 .B crc

 archive format because of its limited portability.