That he truly be single
This should be a given but you’d be surprised how often it is not. You can go out with a guy to discover he’s still living with his ex, but they’re “technically no longer together.” You can discover he broke up with his ex, but it’s more like a break, and they’re going to touch base in a few months to see how they feel. Maybe he’s still with his partner for all sorts of “reasons,” like she’s going through something rough and he doesn’t want to abandon her now, but he swears he fell out of love with her a long time ago. Yeah…no. You don’t need to be “understanding” of any of these situations. You can simply set a standard by which you only date people who are truly single.