Even if the bride-to-be has been sporting a diamond ring for years, in many Jewish communities, the couple isn't truly engaged until a tena'im (a document detailing the conditions of the engagement) is signed. Breaking an engagement after it's signed is considered extremely dishonorable, so if a tena'im is used, it's almost always signed the day of the wedding . This means, of course, that the couple isn't technically engaged until their wedding day.