> cause after the discussion, the "my" prefix had to appear
> only in xsl:function/@name.

also where the function is called, but declaring the namespace would
only change the error message to get unknown function (as xsl;function
will be silently ignored by an xslt 1 processor if you put version=2.0)

    <xsl:value-of select="
              my:i18n-get-properties(i18n)
              ^^^

David