Say you’re a high society lady in the Victorian-era United States. And say a charming bachelor catches your eye across the dance floor and wants to get to know you. He could a.) find someone of good standing to introduce you to him, b.) risk his reputation and the wrath of your chaperone by daring to speak to you himself, or c.) clandestinely slip you a small card printed with a picture or a joke asking if he could walk you home.

Escort cards became popular in the late 19th century—a time when many women couldn’t go out without a chaperone watching their behavior, says Barbara Rusch, an expert in and collector of Victorian ephemera. To bypass the strict social rules of the day, Rusch says a man would surreptitiously slip an escort card to a woman he fancied, who might hide it “inside her glove or behind a fan.”

Though it’s not clear how seriously people took these cards, or how effective they were, acquaintance card collector Alan Mays thinks most of them “were intended to start up conversations, break the ice, or innocently flirt.”

View Images This card was likely used to reply to a “May I. C. U. Home” card. Photograph courtesy Alan Mays

Escort cards mimicked Victorian calling cards, which members of the upper classes left at each other’s houses to introduce themselves, further a relationship, give congratulations, or express condolence.

“The exchange of calling cards in the late 19th century served as a formal means of maintaining social contacts,” Mays says. “In contrast, acquaintance cards were lighthearted and humorous, and they parodied the conventional etiquette associated with calling cards.” This can be especially seen in the personalized acquaintance cards of people like “James L. Gallas, Kissing Rouge” or “E. L. Muellich, Wholesale and Retail Dealer in Love Kisses and Up-to-date Hugs.”

Even if some of the cards were meant as jokes, not everyone was laughing. Rusch says “parents were very fearful of this kind of secret communication.” They worried that the wrong kind of man, with the wrong kind of intentions, would slip an innocent lady an escort card. And that wasn’t unfounded: while some cards were modest and polite, others were basically catcalls. But absent from this concern was whether a woman might want to receive a card from someone she fancied, or even give one herself to a man—or a woman.

Most acquaintance cards were probably given to women by men—they begin “Dear Miss,” or “Fair Lady,” or show a picture of a man walking a woman home. But some were more ambiguous about who was doing the sending and who the receiving.

In addition to “May I. C. U. Home?”, Mays has found a companion card that says “You May C Me Home To-Night,” suggesting that both men and women may have had cards up their sleeves. Some cards had a space for the giver to write his or her name, and Mays has found two examples in which that name is female. One reads “I Am Anna ‘Butch’ Engle Who The Devil Are You?” (where the word “Devil” is denoted by a picture of one). The other appears to be given to a woman by a woman. It reads, in part: “Miss Smith, Your beau I wish to be … Yours Truly, Alice Ramsey.”

Mays says it’s possible that Ramsey’s card was a printer’s proof made “with a random name,” or that the “Smith” it went to wasn’t really a “Miss.” However, given that these cards were meant for clandestine communication, it’s not hard to imagine that some women (or men) may have used them to meet at a time when same-sex affection was viewed as not only inappropriate, but morally wrong.

The need for escort cards faded along with chaperones and other societal norms of the time. Victorian social conventions began to break down at the turn of the century, around the time that women started riding bicycles with other young people—unsupervised.

“This was considered something quite scandalous, because they were ditching these chaperones,” says Rusch of women’s bicycling.

As the century marched on, social life for young people only continued to evolve (the Model T Ford, for example, allowed men and women to get even further away from chaperones). Without the strict chaperone structure that had made escort cards appealing, Rusch says that “these cards fell by the wayside.”

Manufacturers still sold acquaintance cards until at least the mid-20th century, but by that point they were likely viewed as novelties. Today, they seem a quaint vestige of the past, as many men and women now prefer to send their surreptitious messages via a more modern device: the cell phone.