The tag `<tc:selectOneChoice/>` create a dropdownbox, which contain
`<tc:selectItem/>` for static entries or
`<tc:selectItems value="\#{controller.list}"/>` for entries from a controller.

Tag Library Documentation: | |

Dropdown Box with hardcoded items. The second item is disabled. To disable an item, use the `itemDisable` attribute.

    <tc:selectOneChoice label="Dropdown Box"/>

Select a person. The label of the item is shown in the dropdownbox. After submitting, the value of the item is shown in the outputfield. So, if 'Alice' is selected, the text in the outputfield is 'Alice Anderson'.

    <tc:selectItem itemLabel="Alice" itemValue="Alice Anderson"/>

Select a planet and a moon. The list of moons depends on the selected planet. The planet-dropdownbox contain a `<f:ajax render="moonbox"/>`. With it, the moon-dropdownbox will be rerendered, after a value changed in planet-dropdownbox.

    <tc:selectOneChoice label="Planet"
          value="\#{selectOneChoiceController.planet}">
      <f:selectItems value="\#{selectOneChoiceController.planets}"/>
      <f:ajax render="moonbox"/>
    </tc:selectOneChoice>
    <tc:selectOneChoice id="moonbox" label="Moon">
      <f:selectItems value="\#{selectOneChoiceController.moons}"/>
    </tc:selectOneChoice>