diff --git a/docs/design/autoware-architecture/sensing/data-types/point-cloud.md b/docs/design/autoware-architecture/sensing/data-types/point-cloud.md
index 2a5ff323f05..37ef8e8bdfc 100644
--- a/docs/design/autoware-architecture/sensing/data-types/point-cloud.md
+++ b/docs/design/autoware-architecture/sensing/data-types/point-cloud.md
@@ -161,6 +161,10 @@ In the `PointXYZIRCT` and `PointXYZIRC` types, `R` field represents return mode
 | `1`             | Strongest            |
 | `2`             | Last                 |
 
+!!! note
+
+    The `PointXYZIRC` includes a padding field named `padding`, which is of size `UINT8` and serves for memory alignment purposes for `return_type`.
+
 ### Channel
 
 The channel field is used to identify the vertical channel of the laser that measured the point.