diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..92fe151
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,22 @@
+# Changelog
+
+## 0.5
+
+* Allow specifying cached or customized merge rules.
+
+## 0.4 (2018-01-04)
+
+* Use the schema to determine the merge rules.
+* Allow specifying a custom local or remote schema.
+
+## 0.3 (2015-12-04)
+
+* Use relative imports.
+
+## 0.2 (2015-12-01)
+
+* Move repository to open-contracting organization.
+
+## 0.1 (2015-11-29)
+
+First release.
diff --git a/README.rst b/README.rst
index 547c182..03678f6 100644
--- a/README.rst
+++ b/README.rst
@@ -101,3 +101,13 @@ path. Full absolute paths can be used too:
 
    # Use relese-schema.json using absolute path
    ocdsmerge.merge(releases, '/some/full/path/release-schema.json')
+
+Using pre-processed release schema
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. code:: python
+
+   # Extract the merging rules from the schema
+   merge_rules = ocdsmerge.get_merge_rules('release-schema.json')
+   # Use the merging rules
+   ocdsmerge.merge(releases, merge_rules=merge_rules)
diff --git a/ocdsmerge/__init__.py b/ocdsmerge/__init__.py
index e56a1de..ae53f99 100644
--- a/ocdsmerge/__init__.py
+++ b/ocdsmerge/__init__.py
@@ -1 +1 @@
-from .merge import merge, merge_versioned  # noqa
+from .merge import merge, merge_versioned, get_merge_rules  # noqa
diff --git a/ocdsmerge/merge.py b/ocdsmerge/merge.py
index 06e7593..b5a79ba 100644
--- a/ocdsmerge/merge.py
+++ b/ocdsmerge/merge.py
@@ -53,7 +53,7 @@ def remove_number_path(path):
     return tuple(item for item in path if not isinstance(item, int))
 
 
-def process_schema(schema):
+def get_merge_rules(schema):
     schema = schema or get_latest_schema_uri()
     if schema.startswith('http'):
         deref_schema = jsonref.load_uri(schema)
@@ -156,10 +156,11 @@ def process_flattened(flattened):
     return processed
 
 
-def merge(releases, schema=None):
+def merge(releases, schema=None, merge_rules=None):
     ''' Takes a list of releases and merge them making a
     compiledRelease suitible for an OCDS Record '''
-    merge_rules = process_schema(schema)
+    if not merge_rules:
+        merge_rules = get_merge_rules(schema)
     merged = collections.OrderedDict({("tag",): ['compiled']})
     for release in sorted(releases, key=lambda rel: rel["date"]):
         release = release.copy()
@@ -184,10 +185,11 @@ def merge(releases, schema=None):
     return unflatten(merged)
 
 
-def merge_versioned(releases, schema=None):
+def merge_versioned(releases, schema=None, merge_rules=None):
     ''' Takes a list of releases and merge them making a
     versionedRelease suitible for an OCDS Record '''
-    merge_rules = process_schema(schema)
+    if not merge_rules:
+        merge_rules = get_merge_rules(schema)
     merged = collections.OrderedDict()
     for release in sorted(releases, key=lambda rel: rel["date"]):
         release = release.copy()