diff --git a/Documentation/i2c/i2c-protocol.rst b/Documentation/i2c/i2c-protocol.rst
index 66adac3a5afd..9a4ac944cf9d 100644
--- a/Documentation/i2c/i2c-protocol.rst
+++ b/Documentation/i2c/i2c-protocol.rst
@@ -11,7 +11,7 @@ Key to symbols
 S               Start condition
 P               Stop condition
 Rd/Wr (1 bit)   Read/Write bit. Rd equals 1, Wr equals 0.
-A, NA (1 bit)   Accept and reverse accept bit.
+A, NA (1 bit)   Acknowledge (ACK) and Not Acknowledge (NACK) bit
 Addr  (7 bits)  I2C 7 bit address. Note that this can be expanded as usual to
                 get a 10 bit I2C address.
 Comm  (8 bits)  Command byte, a data byte which often selects a register on