diff --git a/mods/CORE/flowlib/API.md b/mods/CORE/flowlib/API.md
index f3282c975..20e85036b 100644
--- a/mods/CORE/flowlib/API.md
+++ b/mods/CORE/flowlib/API.md
@@ -7,7 +7,6 @@ Return true if a sphere of <radius> at <realpos> collide with node at <nodepos>.
 * nodepos: position
 * radius: number
 
-
 ## flowlib.is_water(pos)
 Return true if node at <pos> is water, false overwise.
 * pos: position
@@ -38,7 +37,9 @@ Return direction where the water is flowing (to be use to push mobs, items...).
 * node: node
 
 ## flowlib.move_centre(pos, realpos, node, radius)
+Return the pos of the nearest not water block near from <pos> in a sphere of <radius> at <realpos>.
+WARNING: This function is never used in mcl2, use at your own risk. The informations described here may be wrong.
 * pos: position
-* realpos: position
+* realpos: position, position of the entity
 * node: node
 * radius: number
\ No newline at end of file