2.2.8 sectPr Extensions
Any sectPr element specified in [ISO/IEC29500-1:2016] section 17.6.18 is extended by the addition of the footnoteColumns element (section 2.5.1.8).<7> To maintain compatibility with ISO/IEC-29500 implementations, the element’s namespace prefix MUST be specified in an Ignorable attribute ([ISO/IEC29500-3:2015] section 7.2).