Adding TAGS in portfolio items

Are you talking about the original post tags? OR want to use a separate new TAGS taxonomy?

I’m talking about having tags on portfolio items too…Don’t know if the thing would be possibile without massive work.
what do you think?

You just need to register another taxonomy of tags for portfolio post type.

Please check this https://codex.www.ads-software.com/Function_Reference/register_taxonomy

Let me explain better what I would like to do, since I’m no PHP expert:
https://docs.google.com/file/d/0B7ckUZUdHpRpMk9MazFYZEt0XzA/edit?usp=sharing

A panel for tags on each item would be great. if it’s too complicated to do, could somebody just paste the function I need? is it too much to ask? ??
thanks!