diff --git a/317-Protocol.mediawiki b/317-Protocol.mediawiki
index 331ed60..9fafb24 100644
--- a/317-Protocol.mediawiki
+++ b/317-Protocol.mediawiki
@@ -437,7 +437,7 @@ The following is what most people think of when they say 'update mask' and 'upda
 
 Inside this method, many different bitwise masks are compared to the player's flag, and if the mask is set, logic is performed. These masks are frequently called update masks. A list of player update masks are below:
 
-* '''0x400''' Not much is known about this mask, other than that the last value read is a sprite direction id.
+* '''0x400''' The 0x400 mask is used to update the player so they appear to be asynchronously animating and walking.
 
 
 * '''0x100''' The 0x100 mask is responsible for player graphics updating. The data associated is a little-endian unsigned short which represents the graphics id, and an int which is the graphics delay.