--- a/svghmi/gen_index_xhtml.xslt	Thu Feb 13 09:43:35 2020 +0100
+++ b/svghmi/gen_index_xhtml.xslt	Fri Feb 14 10:29:10 2020 +0100
@@ -116,6 +116,16 @@
       <xsl:apply-templates mode="inline_svg" select="@* | node()"/>
     </xsl:copy>
   </xsl:template>
+  <xsl:template mode="inline_svg" match="svg:svg[@viewBox!=concat('0 0 ', @width, ' ', @height)]">
+    <xsl:message terminate="yes">
+      <xsl:text>Scale other than 1.000 in Inkscape's document properties is not supported</xsl:text>
+    </xsl:message>
+  </xsl:template>
+  <xsl:template mode="inline_svg" match="sodipodi:namedview[@units!='px' or @inkscape:document-units!='px']">
+    <xsl:message terminate="yes">
+      <xsl:text>All units must be set to "px" in Inkscape's document properties</xsl:text>
+    </xsl:message>
+  </xsl:template>
   <xsl:template match="/">
     <xsl:comment>
       <xsl:text>Made with SVGHMI. https://beremiz.org</xsl:text>

--- a/svghmi/gen_index_xhtml.ysl2	Thu Feb 13 09:43:35 2020 +0100
+++ b/svghmi/gen_index_xhtml.ysl2	Fri Feb 14 10:29:10 2020 +0100
@@ -121,6 +121,14 @@
         attrib "width" > 100vw
         apply "@* | node()", mode="inline_svg";
     }
+    /* ensure that coordinate in CSV file generated by inkscape are in default reference frame */
+    template "svg:svg[@viewBox!=concat('0 0 ', @width, ' ', @height)]", mode="inline_svg" {
+        error > ViewBox settings other than X=0, Y=0 and Scale=1 are not supported
+    }
+    /* ensure that coordinate in CSV file generated by inkscape match svg default unit */
+    template "sodipodi:namedview[@units!='px' or @inkscape:document-units!='px']", mode="inline_svg" {
+        error > All units must be set to "px" in Inkscape's document properties
+    }
 
     /*const "mark" > =HMI=\n*/