I gave the link to CUSMA. I didn't think I needed to copy/paste the relevant bits but since you asked, per article 32.10 items 1(a) and 1(b) relates to a "non-market country free trade agreements with which no party has signed a free trade agreement":
Article 32.10: Non-Market Country FTA
- For the purposes of this Article:
non-market country is a country:
(a) that on the date of signature of this Agreement, a Party has determined to be a non-market economy for purposes of its trade remedy laws; and
(b) with which no Party has signed a free trade agreement.
I don't think I'm leaving anything out.