FARZ KIFA’I فرض كفاى
A command which is imperative (jarz) upon all Muslims, but which if one person in eight or ten performs it, it is sufficient (kifa’i), or equivalent to all having performed it.
They are generally held to be five in number: (1) To return a salutation; (2) To visit the sick and inquire after their welfare; (3) To follow a bier on foot to the grave; (4) To accept an invitation to dinner; (5) Replying to a sneeze. [SNEEZING.]
They are also said to be six or seven in number, when there are added one or two of the following: (1) To give advice when asked for it; (2) To help a Muslim to verify his oath; (3) To assist a person in distress. ‘Abdu ‘l-Haqq says this last injunction applies to all cases, whether that of a Muslim or an infidel. (Mishkat, book v c I part 1).
Based on Hughes, Dictionary of Islam