ex {if not seen}?

Like you said, it's {if not seen. It works exactly the same way as seen, just reversed.

If you're having a problem with this, maybe you could provide more information.

oh i didnt know that existed

I always open a new game to test things out. Can't hurt anything that way.

You can even open a cute, little Squiffy in Scratchpad via this very site's documentation section:

https://docs.textadventures.co.uk/squiffy/scratchpad/

It is an older version of Squiffy, but most things that aren't written by you in Javascript work about the same.

You can also save a Squiffy story file as a GitHub Gist and load the Gist directly in that scratchpad.

Want to edit some stupid game I just saved as a Gist?

https://docs.textadventures.co.uk/squiffy/scratchpad/?gistid=02338c1669580fac501207ddba62c98e&filename=Get%20the%20Gist.squiffy

Want to load your own Gist?

Go to that first link and click the "Load Gist" button.

I learn most things by trial and error.