diff --git a/src/plugins/zeroExport/SMLCRCTable.h b/src/plugins/zeroExport/SMLCRCTable.h
index 8f6c1c19..9aee2987 100644
--- a/src/plugins/zeroExport/SMLCRCTable.h
+++ b/src/plugins/zeroExport/SMLCRCTable.h
@@ -5,6 +5,14 @@
 
 #ifdef ARDUINO
 #include <Arduino.h>
+
+
+/*
+ * This mysterious table is just the CRC of each possible byte. It can be
+ * computed using the standard bit-at-a-time methods. The polynomial can
+ * be seen in entry 128, 0x8408. This corresponds to x^0 + x^5 + x^12.
+ * Add the implicit x^16, and you have the standard CRC-CCITT.
+ */
 static const uint16_t smlCrcTable[256] PROGMEM =
 #else
 static const uint16_t smlCrcTable[256] =