diff --git a/xproc/src/main/xml/specification.xml b/xproc/src/main/xml/specification.xml
index ec1724d9c..b46218c86 100644
--- a/xproc/src/main/xml/specification.xml
+++ b/xproc/src/main/xml/specification.xml
@@ -501,10 +501,10 @@ document has no base URI.
If a step serializes a document whose document properties contain a
serialization property, it must use these
serialization properties. If the step itself allows specification of serialization properties
- (usually by a option), both sets of serialization
- properties are merged. Serialization properties specified on the step itself have
- precedence over serialization properties specified with the serialization
- document property.
+ (usually by a option), the serialization
+ properties are merged. Serialization properties specified on the document have
+ precedence over serialization properties specified on the step.
+ See .
@@ -525,7 +525,36 @@ processor must assure that the content-type property is appropriate
If a step changes the content-type in this way, it must also
remove the serialization property.
-
+
+Managing properties
+
+In XProc 3.0, the rules for merging serialization properties stated that
+the properties on the step took precedence. In practice, all of the steps with a
+ option explicitly stated the opposite. This
+inconsistency was confusing. Changing the behavior of the steps would
+likely break many existing pipelines, so the merging behavior has been changed
+in this specification instead.
+
+A pipeline author who wants to explicitly override all the serialization
+properites for a document can easily do so with p:set-properties
+before the step where they want the override to apply.
+
+Explicitly overriding only some properties is also
+possible, but somewhat more complicated. The following p:set-attributes
+example removes only the indent property from a document’s serialization properties,
+leaving all other properties intact:
+
+]]>
+
+Any property or set of properties can be removed or updated in this way.
+
+
+
Document Types