<quote>
15.6.1 <style:header>
The <style:header> element specifies a style for a header element in a <style:master-page> element.
15.6.2 <style:footer>
The <style:footer> element specifies a style for a footer element in a <style:master-page> element.
15.6.3 <style:header-left>
The <style:header-left> element specifies a style for a header element for a left page, if different from the right page in a <style:master-page> element.
15.6.4<style:footer-left>
The <style:footer-left> element specifies a style for a footer element for a left page, if different from the right page for a <style:master-page> element.
</quote>
In all cases the formulation "specifies a style" is used. But these elements don't actually specify a style, they contain the content of the header/footer.
In 1.2 draft6 we had the following text:
<quote>
The header and footer elements specify the content of headers and footers. They are contained within a master page element. The <style:header> and <style:footer> elements contain the content of headers and footers.
</quote>