Is there a way to add a member to a card as just an observer?

[Brian Evans]

I want to be able to assign a single member as the owner, but there are time where I would like to add other members just as observers and allow notification rules based on that (but not confuse them on who owns the card/task).  This would be especially helpful as well if the filter would also allow the differentiation.

This is different that adding observers to a list.

[Caity]

Hi Brian,

Right now, there isn't a way to subscribe other users to a card without adding them as members of that card.

However, if these are members of the board already, you can @ mention them in a comment on the card and suggest that they subscribe to the card. If they subscribe, they'll then receive updates about changes to that card, without having to be a member.

We have some more information about subscribing here: http://help.trello.com/article/799-subscribing-to-cards-lists-and-boards

[Matthew N]

Hey Brian,

Permissions are board specific, and there's not currently a way to make permissions based on list or card. 

You can share your interest with the development team by sending an email to feature-ideas@trello.com