diff --git a/serialization/src/main/kotlin/net/corda/serialization/internal/amqp/CustomSerializer.kt b/serialization/src/main/kotlin/net/corda/serialization/internal/amqp/CustomSerializer.kt
index 8eb4c6c60a..471546369e 100644
--- a/serialization/src/main/kotlin/net/corda/serialization/internal/amqp/CustomSerializer.kt
+++ b/serialization/src/main/kotlin/net/corda/serialization/internal/amqp/CustomSerializer.kt
@@ -30,7 +30,8 @@ abstract class CustomSerializer<T : Any> : AMQPSerializer<T>, SerializerFor {
     open val additionalSerializers: Iterable<CustomSerializer<out Any>> = emptyList()
 
     /**
-     * This custom serializer is also allowed to deserialize these classes.
+     * This custom serializer is also allowed to deserialize these classes. This allows us
+     * to deserialize objects into completely different types, e.g. `A` -> `sandbox.A`.
      */
     open val deserializationAliases: Set<Class<*>> = emptySet()
 
@@ -57,6 +58,12 @@ abstract class CustomSerializer<T : Any> : AMQPSerializer<T>, SerializerFor {
     abstract fun writeDescribedObject(obj: T, data: Data, type: Type, output: SerializationOutput,
                                       context: SerializationContext)
 
+    /**
+     * [CustomSerializerRegistry.findCustomSerializer] will invoke this method on the [CustomSerializer]
+     * that it selects to give that serializer an opportunity to customise its behaviour. The serializer
+     * can also return `null` here, in which case [CustomSerializerRegistry] will proceed as if no
+     * serializer is available for [declaredType].
+     */
     open fun specialiseFor(declaredType: Type): AMQPSerializer<T>? = this
 
     /**
diff --git a/serialization/src/main/kotlin/net/corda/serialization/internal/amqp/Schema.kt b/serialization/src/main/kotlin/net/corda/serialization/internal/amqp/Schema.kt
index 26dc084587..36ac18bfe6 100644
--- a/serialization/src/main/kotlin/net/corda/serialization/internal/amqp/Schema.kt
+++ b/serialization/src/main/kotlin/net/corda/serialization/internal/amqp/Schema.kt
@@ -18,6 +18,11 @@ val amqpMagic = CordaSerializationMagic("corda".toByteArray() + byteArrayOf(1, 0
 fun typeDescriptorFor(typeId: TypeIdentifier): Symbol = Symbol.valueOf("$DESCRIPTOR_DOMAIN:${AMQPTypeIdentifiers.nameForType(typeId)}")
 fun typeDescriptorFor(type: Type): Symbol = typeDescriptorFor(forGenericType(type))
 
+/**
+ * Repackages a naked, non-primitive [obj] as a [DescribedType]. If [obj] is primitive, [Binary] or already
+ * an instance of [DescribedType]] then it is returned unchanged. This allows Corda to search for a serializer
+ * capable of handling instances of [type].
+ */
 fun redescribe(obj: Any?, type: Type): Any? {
     return if (obj == null || obj is DescribedType || obj is Binary || forGenericType(type).run { isPrimitive(this) || this == TopType }) {
         obj
diff --git a/serialization/src/main/kotlin/net/corda/serialization/internal/model/TypeIdentifier.kt b/serialization/src/main/kotlin/net/corda/serialization/internal/model/TypeIdentifier.kt
index 274cd50dda..2697b107a8 100644
--- a/serialization/src/main/kotlin/net/corda/serialization/internal/model/TypeIdentifier.kt
+++ b/serialization/src/main/kotlin/net/corda/serialization/internal/model/TypeIdentifier.kt
@@ -210,7 +210,8 @@ sealed class TypeIdentifier {
         override fun getLocalType(classLoader: ClassLoader): Type {
             // We need to invoke ClassLoader.loadClass() directly, because
             // the JVM will complain if Class.forName() returns a class
-            // that has a name other than the requested one.
+            // that has a name other than the requested one. This will happen
+            // for "transformative" class loaders, i.e. `A` -> `sandbox.A`.
             val rawType = classLoader.loadClass(name)
             if (rawType.typeParameters.size != parameters.size) {
                 throw IncompatibleTypeIdentifierException(