- * An update generated by the underlying Channel itself which contains some new information the
- * ChannelMonitor should be made aware of.
+ * An update generated by the underlying channel itself which contains some new information the
+ * [`ChannelMonitor`] should be made aware of.
+ *
+ * Because this represents only a small number of updates to the underlying state, it is generally
+ * much smaller than a full [`ChannelMonitor`]. However, for large single commitment transaction
+ * updates (e.g. ones during which there are hundreds of HTLCs pending on the commitment
+ * transaction), a single update may reach upwards of 1 MiB in serialized size.