Three features identify the literal definition. Request separates it from a report; refraining identifies what is requested; and authoritative stance characterizes a straightforward prohibition.
“He is not writing today.” — This is a report, not an instruction to anyone.
“Do not write today.” — This asks the addressee to refrain from writing.
“Please do not write today.” — The action requested is still refraining, but social context may make its force a courteous request.
Negativity alone does not establish prohibition. The central question is whether the addressee is being asked to refrain.