diff --git a/Gemfile.devel b/Gemfile.devel
new file mode 100644
index 0000000..c677e08
--- /dev/null
+++ b/Gemfile.devel
@@ -0,0 +1 @@
+gem "metanorma-standoc", git: "https://github.com/metanorma/metanorma-standoc", branch: "feature/ext-flavor"
diff --git a/lib/metanorma/ribose/biblio-standoc.rng b/lib/metanorma/ribose/biblio-standoc.rng
index 70a0502..6588af6 100644
--- a/lib/metanorma/ribose/biblio-standoc.rng
+++ b/lib/metanorma/ribose/biblio-standoc.rng
@@ -72,6 +72,9 @@ standards defining organization, and that is rendered in a distinct manner</a:do
 from other documents in the same doctype</a:documentation>
       </ref>
     </optional>
+    <ref name="flavor">
+      <a:documentation>Flavour of Metanorma used to process this document</a:documentation>
+    </ref>
     <optional>
       <ref name="editorialgroup">
         <a:documentation>Groups associated with the production of the standards document, typically within
@@ -113,6 +116,16 @@ a standards definition organization</a:documentation>
   <define name="DocumentSubtype">
     <text/>
   </define>
+  <define name="flavor">
+    <element name="flavor">
+      <ref name="MetanormaFlavor"/>
+    </element>
+  </define>
+  <define name="MetanormaFlavor">
+    <a:documentation>This is in fact an enum, as of this writing: standoc iso generic ietf ieee itu nist ogc csa cc iho ribose jis iec bsi bipm plateau.
+However we prefer not to hardcode it, given ongoing extension.</a:documentation>
+    <text/>
+  </define>
   <define name="editorialgroup">
     <a:documentation>A group associated with the production of the standards document, typically within
 a standards definition organization</a:documentation>
diff --git a/lib/metanorma/ribose/biblio.rng b/lib/metanorma/ribose/biblio.rng
index 1a206da..9cfa89f 100644
--- a/lib/metanorma/ribose/biblio.rng
+++ b/lib/metanorma/ribose/biblio.rng
@@ -1382,18 +1382,7 @@ Applies whether the resource has already been created or not, and whether it is
   <define name="bdate">
     <a:documentation>Significant date in the lifecycle of the bibliographic item, including its production and its access</a:documentation>
     <element name="date">
-      <attribute name="type">
-        <a:documentation>The phase of the production of or access to a bibliographic item</a:documentation>
-        <choice>
-          <ref name="BibliographicDateType"/>
-          <text/>
-        </choice>
-      </attribute>
-      <optional>
-        <attribute name="text">
-          <a:documentation>An optional textual description of the date, especially when a Gregorian date is not applicable</a:documentation>
-        </attribute>
-      </optional>
+      <ref name="bDateAttributes"/>
       <optional>
         <choice>
           <group>
@@ -1416,6 +1405,20 @@ Applies whether the resource has already been created or not, and whether it is
       </optional>
     </element>
   </define>
+  <define name="bDateAttributes">
+    <attribute name="type">
+      <a:documentation>The phase of the production of or access to a bibliographic item</a:documentation>
+      <choice>
+        <ref name="BibliographicDateType"/>
+        <text/>
+      </choice>
+    </attribute>
+    <optional>
+      <attribute name="text">
+        <a:documentation>An optional textual description of the date, especially when a Gregorian date is not applicable</a:documentation>
+      </attribute>
+    </optional>
+  </define>
   <define name="docidentifier">
     <a:documentation>An identifier of a bibliographic item in an international standard scheme</a:documentation>
     <element name="docidentifier">
@@ -1884,6 +1887,10 @@ Detailed in https://www.relaton.org/model/relations/</a:documentation>
       <value>hasAnnotation</value>
       <value>draftOf</value>
       <value>hasDraft</value>
+      <value>preliminaryDraftOf</value>
+      <value>hasPreliminaryDraft</value>
+      <value>revisionDraftOf</value>
+      <value>hasRevisionDraft</value>
       <value>editionOf</value>
       <value>hasEdition</value>
       <value>updates</value>
diff --git a/lib/metanorma/ribose/relaton-ribose.rng b/lib/metanorma/ribose/relaton-ribose.rng
index 0e95117..274147b 100644
--- a/lib/metanorma/ribose/relaton-ribose.rng
+++ b/lib/metanorma/ribose/relaton-ribose.rng
@@ -30,6 +30,7 @@
       <optional>
         <ref name="docsubtype"/>
       </optional>
+      <ref name="flavor"/>
       <ref name="editorialgroup"/>
       <zeroOrMore>
         <ref name="ics"/>
diff --git a/spec/metanorma/base_spec.rb b/spec/metanorma/base_spec.rb
index ee3d2dd..7c5d48c 100644
--- a/spec/metanorma/base_spec.rb
+++ b/spec/metanorma/base_spec.rb
@@ -125,6 +125,7 @@
            </copyright>
            <ext>
              <doctype>standard</doctype>
+      <flavor>ribose</flavor>
              <editorialgroup>
                <committee type="A">TC</committee>
                <committee type="A1">TC1</committee>
@@ -226,6 +227,7 @@
            </copyright>
            <ext>
              <doctype abbreviation="Code">code</doctype>
+      <flavor>ribose</flavor>
            </ext>
          </bibdata>
          <metanorma-extension>
@@ -337,6 +339,7 @@
           </copyright>
           <ext>
           <doctype>standard</doctype>
+      <flavor>ribose</flavor>
           </ext>
         </bibdata>
       OUTPUT
@@ -402,6 +405,7 @@
           </copyright>
           <ext>
           <doctype>standard</doctype>
+      <flavor>ribose</flavor>
           </ext>
         </bibdata>
       OUTPUT
@@ -467,6 +471,7 @@
         </copyright>
         <ext>
           <doctype>standard</doctype>
+      <flavor>ribose</flavor>
         </ext>
       </bibdata>
     OUTPUT
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 1b12a1a..1c8a682 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -147,6 +147,7 @@ def boilerplate(xmldoc)
       </copyright>
       <ext>
       <doctype>standard</doctype>
+      <flavor>ribose</flavor>
       </ext>
     </bibdata>
                         <metanorma-extension>