[TYPO3-mvc] Why is this section uknown? Can layouts only have one section?

[Stephen Bungert]

I have a layout like this:

<div class="portfolio portfolioItem portfolioSingle">
 <f:render section="itemMetatags" />
 <f:render section="itemSingle" />
</div>

<f:render section="itemMetatags" /> is new, if I take it away, everything is
ok. But if I leave it there I get an error message:

"#1227108982: Could not render unknown section "itemMetatags" in
Tx_Fluid_View_TemplateView used by
Tx_SbPortfolio2_Controller_ItemController"

I have saved the section template here:

"Resources/Private/Templates/Item/Metatags.html"

---

<f:render section="itemSingle" /> works ok and has a template saved here:

"Resources/Private/Templates/Item/Single.html"

so why does the itemMetatags section cause an error?