Use might to express possibility, or when the result of an action is unknown or variable. Use may for permission.
In technical documentation, might and may are vague and can convey uncertainty. Rewrite sentences in the imperative form if you can do so without changing their meaning.
Preferred
Discouraged
Additional voice call capacity requires the purchase of additional software and might require additional hardware.
Additional voice call capacity requires the purchase of additional software and may require additional hardware.
The fan might continue to rotate after you remove the cover.
The fan may continue to rotate after you remove the cover.
