the delphic expanse

When I post a story at the Archive, I only can choice one name of the characters, of only one warning or only one pairing. I can only select one.
Untill now, that wasn't a big problem. But I hope to post a new story with at least three pairings and all lot of other characters who all have their part (without pairing).
Am I missing something and should I pressed a certain key or sets of keys at the keyboard to select more then one choice?

If you hold down command on a mac or ctrl I believe on a pc (correct me if I'm wrong pc people) you should be able to select more than one.

Ooo.. I feel so stupid. I thought I pressed the right button. Now I pressed Control and it works! Thanks!

No worries. Every single time I press shift first! Then, I remember it's command!