I have this darling book, Love Letters Made Easy, copyright 1910 by Edward Clode, New York. Today seems like a good day to learn about the “Silent Messengers of Love,” which is the title of the first chapter.
Did you know that how and where you arrange a postage stamp sends a message? Well, it does. I’ve copied the advice here, just as it was set in the book, inconsistencies and all…
Upside-down, on the left corner — I love you.
Same corner, crosswise — My heart is another’s.
Straight up and down — Good-by, sweetheart.
Upside down, on right corner — Write no more.
In the left-hand corner — I hate you.
Bottom corner, at the left — I seek your acquaintance.
On the right-hand corner, at a right angle — Do you love me?
Top corner, at the right — I wish your friendship.
On the line with surname — Accept my love.
On the line with surname, upside down — I am engaged.
At right angle, same place — I long to see you.
In the middle, at right-hand edge — Write immediately.
In the center, at the top — Yes.
In the center, at the bottom — No.
Right. Made easy.
ginnygram 
I’ll have to remember to put it in the left-hand corner on my phone bill.
I’ll have to remember to put it in the left-hand corner when I pay my phone bill.