The term 'DO NOT DELETE' can be summarized by two crossword solutions: STET (4 letters) and LEAVEIN (7 letters). STET is a Latin word meaning 'let it stand' and is used in proofreading to indicate that the text should remain unchanged. LEAVEIN is an instruction to not delete something, usually a file or document. Both of these terms are used to indicate that something should not be removed or altered.