aLiterally “he changed his discernment”
bLiterally “my father is king” whereas 1 Sam 21:10(9) has “Achish.” “Abimelech” is perhaps an honorific title, since its literal meaning suggests a legitimate right to rule
cThe Hebrew Bible counts the superscription as the first verse of the psalm; the English verse number is reduced by one

In other versions

Of David, when he changed his behavior before Abimelech, so that he drove him out, and he went away.

Of David. When he pretended to be insane before Abimelek, who drove him away, and he left.

Concerning David, when he pretended to be insane in the presence of Abimelech, who drove him out, and he departed.

A psalm of David, regarding the time he pretended to be insane in front of Abimelech, who sent him away.

A Psalm of David, when he changed his behaviour before Abimelech; who drove him away, and he departed.

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