Change xlink from/label/to attributes. They're no longer optional

diff --git a/docbook/relaxng/docbook/src/xlink.rnc b/docbook/relaxng/docbook/src/xlink.rnc
index 5ed25eb22dd9b1878de06e1025e46840e175a33a..430243f9fefc23302039d3b7294385c3c3e7aac2 100644 (file)
--- a/docbook/relaxng/docbook/src/xlink.rnc
+++ b/docbook/relaxng/docbook/src/xlink.rnc
@@ -41,19 +41,19 @@ db.xlink.from.attribute =
    [
       db:refpurpose [ "Specifies the XLink traversal-from" ]
    ]
-   attribute xlink:from { xsd:NMTOKEN }?
+   attribute xlink:from { xsd:NMTOKEN }
 
 db.xlink.label.attribute =
    [
       db:refpurpose [ "Specifies the XLink label" ]
    ]
-   attribute xlink:label { xsd:NMTOKEN }?
+   attribute xlink:label { xsd:NMTOKEN }
 
 db.xlink.to.attribute =
    [
       db:refpurpose [ "Specifies the XLink traversal-to" ]
    ]
-   attribute xlink:to { xsd:NMTOKEN }?
+   attribute xlink:to { xsd:NMTOKEN }
 
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