diff --git a/mei2ly.xsl b/mei2ly.xsl
index b8d7c6f..acb2f70 100644
--- a/mei2ly.xsl
+++ b/mei2ly.xsl
@@ -838,7 +838,7 @@
       <xsl:call-template name="setRelFontsizeNum" />
     </xsl:if>
     <xsl:if test="@ho or @vo">
-      <!-- not available in MEI -->
+      <!-- not available in MEI4 -->
       <xsl:text>\once \override Staff.Clef.extra-offset = #&apos;</xsl:text>
       <xsl:call-template name="setOffset" />
     </xsl:if>
@@ -1326,6 +1326,7 @@
       <xsl:call-template name="setVisibility" />
     </xsl:if>
     <xsl:if test="@color">
+      <!-- not available in MEI4 -->
       <xsl:text>\tweak color #</xsl:text>
       <xsl:call-template name="setColor" />
     </xsl:if>
diff --git a/supported.md b/supported.md
index 21ae33e..71ae5b1 100644
--- a/supported.md
+++ b/supported.md
@@ -88,6 +88,7 @@ List of supported MEI elements and attributes
   * `@fermata`
   * `@fontsize`
   * `@grace`
+  * *`@ho`*
   * `@lv`
   * `@oct`
   * `@ornam`
@@ -99,6 +100,7 @@ List of supported MEI elements and attributes
   * `stem.visible`
   * `@tie`
   * `@visible`
+  * *`@vo`*
 
 * `<clef>`
   * `@color`
@@ -316,7 +318,7 @@ List of supported MEI elements and attributes
   * `@xml:id`
 
 * `<mRest>`
-  * `@color`
+  * *`@color`*
   * `@copyof`
   * `@dur`
   * `@dur.ges`