I found many versions of autograph-book verses that begin "When this you see, remember me" (or the reverse). Sometimes that line was used alone, or introduced other thoughts expressed in prose.

Remember me when this you see.
Remember me at parting day;
And if my face no more you see,
Look on these lines and think of me.

Remember me when this you see,
Though many a mile apart we be;
And if the grave first be my lot,
Dearest friend, forget me not.

Remember me when this you see,
And place me in your mind.
What others say when far away,
Think not of me unkind.

When this you see, remember me,
And bear me in your mind.
Let all the world say what it may,
Speak of me as you find.

The line "When this you see, remember me, and place me in your mind" occurs in a letter to Sojourner Truth written by her son, Peter Van Wagener, dated 1841. The letter is quoted in the book "Narrative of Sojourner Truth, a Bondswoman of Olden Time...(etc.)" by Olive Gilbert, published in 1875. You can see the text at Documenting the American South, a web site belonging to the University of North Carolina at Chapel Hill.

There is also a book called "When This You See, Remember Me: A Collection of Autograph Verses" by Lillian Morrison, 1961.

There is an interesting collection of autograph book images, including some ornate covers, at Morning Glory Antiques & Jewelry.