From the handy guide: Our Deportment: The Manners, Conduct and Dress of the Most Refined Society, published in 1882.
Suitors (always a man back in those days) and ladies were to observe strict etiquette if they were to be perceived as properly bred and suitable.
For the ladies:
No mixed messages
“A young lady who is not engaged may receive calls and attention from such unmarried gentlemen as she desires, and may accept invitation to ride, to concerts, to theatres, etc. She should use due discretion, however, as to whom she favors by the acceptance of such invitations. A young lady should not allow special attention from anyone to whom she is not specially attracted, because, first, she may do injury to the gentleman in seeming to give his suit encouragement; and, secondly, she may keep away from her those whom she likes better, but will not approach her under the mistaken idea that her feelings are already interested.”
Play hard to get, sort of...
“No well bred lady will too eagerly receive the attentions of a gentlemen, no matter how much she admires him; nor, on the other hand, will she be so reserved as to altogether discourage him.”
“It is only the contemptible flirt that keeps an honorable man in suspense for the purpose of glorifying herself by his attentions in the eyes of friends. Nor would any but a frivolous or vicious girl boast of the offer she has received and rejected.”
For the Gentlemen:
“Gentlemen are at liberty to accept invitations and give them ad libitum. As soon, however, as a young gentleman neglects all others, to devote himself to a single lady, he gives that lady reason to suppose that he is particularly attracted to her, and may give her cause to believe she is to become engaged to him, without telling her so. A gentleman who does not contemplate matrimony should not pay too exclusive attention to any one lady.”
“It is very injudicious, not to say presumptuous, for a gentleman to make a proposal to a young lady on too brief acquaintance. A lady who would accept a gentleman at first sight can hardly possess the discretion needed to make a good wife.”