Why SHOULD you be able to pick out a divorcee from a crowd? Their private business should remain private. Only those who really know them should be involved in their shidduchim. How and why should strangers be trusted with their most private stories or even be trusted to bring forth someone who won’t hurt them a second time?
Their Rabbonim, friends, & family are looking out for their best interests and will be happy to listen if someone has a shidduch for a divorcee. There are forums and shidduch groups you can bring your information to and the chain of information will be implemented. No one has to wear a tag, or be singled out in a crowd because they become available again.