More on Paul VI’s 1967 motu proprio on reestablishing the permanent diaconate. What does a deacon do? This question answered, mostly in a liturgical way:
21. According to the above-mentioned Constitution of the Second Vatican Council it pertains to the deacon, to the extent that he has been authorized by the local Ordinary to attend such functions:
(22.) 1) To assist the bishop and the priest during liturgical actions in all things which the rituals of the different orders assign to him;
2) To administer baptism solemnly and to supply the ceremonies which may have been omitted when conferring it on children or adults;
3) To reserve the Eucharist and to distribute it to himself and to others, to bring it as a Viaticum to the dying and to impart to the people benediction with the Blessed Sacrament with the sacred ciborium;
4) In the absence of a priest, to assist at and to bless marriages in the name of the Church by delegation from the bishop or pastor observing the rest of the requirements which are in the Code of Canon Law[Cf. canons 1095 #2, and 1096.] with Canon 1098 remaining firm and where what is said in regard to the priest is also to be understood in regard to the deacon;
5) To administer sacramentals and to officiate at funeral and burial services;
6) To read the sacred books of Scripture to the faithful and to instruct and exhort the people;
7) To preside at the worship and prayers of the people when a priest is not present;
8) To direct the liturgy of the word, particularly in the absence of a priest;
And some non-liturgical functions:
9) To carry out, in the name of the hierarchy, the duties of charity and of administration as well as works of social assistance.
10) To guide legitimately, in the name of the parish priest and of the bishop, remote Christian communities;
11) To promote and sustain the apostolic activities of laymen.
… but perhaps leaving laywomen to other oversight?
23. All these functions must be carried out in perfect communion with the bishop and with his presbytery, that is to say, under the authority of the bishop and of the priest who are in charge of the care of souls in that place.
24. Deacons, as much as possible, should have their part in pastoral councils.