Honesty, integrity, respect, and trustworthyness to the point of never letting the deepest secrets past the fence post.
Supportiveness in difficult times as well as for life's minor challenges -an example of such minor challenge could be coaching in the playing of the dating game.
Good company to share time with when out doing things together, such as going fishing or whatever your passion may be.
We Aspies tend to be a vulnerable lot. When we come across such gems we need them and they need us too. Get the two sides together with that right kind of thinking and the only outcome can be a win-win situation.
OTOH, as the saying goes, true friends are like diamonds, precious and rare, false friends are like autumn leaves, they are found everywhere.
Take your time and be careful when getting to know your new-found "friend". Be observant and trust your intuition. It is an art in itself and it can be like playing the dating game in some ways
_________________
If "manners maketh man" as someone said
Then he's the hero of the day
It takes a man to suffer ignorance and smile
Be yourself no matter what they say
**Sting, Englishman In New York