This template can be used by editors as an "expression of embarrassment, frustration, disbelief, disgust, shame or general woe" (see Facepalm) i.e., as a light-hearted mockery, amusement at an unlikely lapse, or humorous disbelief at perceived idiocy, forgetfulness or mistake on your own or another editor's part. However, doing so in reference to the mistakes of others is liable to be regarded as a violation of civility.
Its use as an expression of abuse, mockery, or for the denigration of others is unacceptable. If there is any doubt that a recipient would take it in good humor, you should not use it.
Any of the following inline, comment-level templates can be converted into {{Resolved}}-style hatnotes by using {{Resbox}} to put a box around the icon and text.
{{enUici|Wikipedia:List of discussion templates|List of discussion templates]], a more linear table of essentially the same set of templates
Template:Resolved/See also, the smaller family of thread-level hatnote templates, similar to the above but with a box around them; any template above can be converted to one of those with {{Resbox}}