Dictionary / Vocabulary / お忘れなく
おわすれなく
please don't forget; please remember; keep in mind
あなたにはいつも私がついている事をお忘れなく。
Remember I will always be at your back.
例外があることをお忘れなく。
Don't forget that there are exceptions.
手紙の返事をお忘れなく。
Remember to answer his letter.