Letters of urgency (4)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">letters of urgency</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for asap that I've seen before include "At one's earliest convenience" , "Notation meaning with minimum delay" , "Common acronym for quick-as-you-can" , "Notation meaning without delay, fast as you can" , "'At the earliest moment, initially (4)'" .)
(Other definitions for sos that I've seen before include "Mayday call" , "Distress call" , "Morse Code for help" , "Help with dots and dashes" , "request for aid" .)