Note: Should PDb members have scans of such items in their collections, we should be pleased to publish them and include them with this article.
Here are some of the interpretations of the stamp language:
Stamp Positions & Meaning
Upside down, top left corner = I love you
Crosswise on top left corner = My heart is another’s
Centre of envelope, at top = Yes
Center of envelope, at bottom = No
Straight up and down, any position = Goodbye sweetheart
Upside down, top right corner = Write no more
At right angle, top right corner = Do you love me?
At right angle, top left corner = I hate you
Upright top right corner = I desire your friendship
Upright in line with surname = Accept my love
Upside down in line with surname = I am engaged
At right angle in line with the surname = I long to see you
Centred on right edge = Write immediately!