Number of friends in Friends list

I have two questions.

1. One of my friend has 89 friends in his friends list. But when I count, he has only 88.. why?
2. How Can I make me invisible in my friends list so that only he or she that I am friends with can only see me in their friends list? Is this possible? or was it possible before?

thanks in advance.

1. Maybe one of them has blocked you/has his profile hidden. This can be done with Privacy Settings
2. Account > Privacy Settings > View Settings > Search for me on Facebook > Only Friends.

Hope it helped!

thanks but this is the issue.
I did exactly what u said by clicking setting... search only friends.... but....
I can be SEEN by others who are not my friends in the FRIENDS LISTS of them!!

is it possible to hide me in others friends lists so that only my friends ca see me??