Does a child of unknown parentage fall under the definition of an orphan, and can sponsoring him be considered an act of worship?

Orphanhood is the loss of a father before reaching puberty. Showing kindness to an orphan and sponsoring them are among the branches of faith, causes for entering Paradise, and means of drawing close to the Prophet, peace be upon him. Sponsoring an orphan is not limited to their worldly interests but also includes their religious interests, such as upbringing, guidance, and education. Individuals of unknown parentage are subject to the rulings concerning orphans and are more deserving of care. Therefore, their sponsor receives the reward of sponsoring an orphan. However, they must not be attributed to the sponsor or added to the family card due to the resulting loss of lineage and rights. After they reach adulthood, they become non-mahram unless there is a mahram-establishing suckling.