F has no positive valence, and Cl can be a positive valence in compounds formed by elements with higher electronegativity than F, usually as follows:

Chlorine oxides: including stable Cl2O, ClO2 and Cl2O7, unstable Cl2O4, ClO3 and free radical ClO4, etc.

Chlorine-containing acids: including HClO, HClO2, HClO3, HClO4 and corresponding salts.

Fluorinated chloride: including ClF, ClF3 and unstable ClF5.

Finally, there is an NCl3.