The term 'overt' best describes actions that are:

The term 'overt' is used to describe actions or behaviors that are done openly and are easily observable, leaving no room for misunderstanding about intent or meaning. This aligns perfectly with the notion of being openly expressed. When something is overt, it means that it is clear and evident, which is the opposite of being hidden or subtle.

In contrast, the other options describe characteristics that contradict the idea of being overt. Actions that are subtle and ambiguous tend to be less clear and can lead to misinterpretation. Concealed actions, by definition, are hidden from view and therefore not overt. Lastly, actions that are rarely shared do not convey openness, as sharing implies a willingness to express oneself openly. Thus, 'openly expressed' is the best match for the definition of 'overt.'