Keilim used for safek issur (YD 107:1).

Reichah:

• Large oven vs. small oven;
• Measuring 12 esronim of flour.

Meat and milk cooking side by side.

See seforim by Rabbi Cohen at ⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠⁠www.kashrushalacha.com⁠⁠⁠⁠⁠⁠⁠⁠