Catholic encyclopedia on the topic: https://www.newadvent.org/cathen/10198d.htm
"Mercy as it is here contemplated is said to be a virtue influencing one's will to have compassion for, and, if possible, to alleviate another's misfortune."
"The traditional enumeration of the corporal works of mercy is as follows":
> To feed the hungry;
> To give drink to the thirsty;
> To clothe the naked;
> To harbour the harbourless;
> To visit the sick;
> To ransom the captive;
> To bury the dead.
"The spiritual works of mercy are":
> To instruct the ignorant;
> To counsel the doubtful;
> To admonish sinners;
> To bear wrongs patiently;
> To forgive offences willingly;
> To comfort the afflicted;
> To pray for the living and the dead.