A deacon reader passed this along. This question popped up at Zenit and is answered by Fr. Edward McNamara:
Q: In Vietnam, the Eucharistic minister wears a deacon’s stole, as you can see in the attached picture. Is this right? — N.T., Vietnam A: Our reader accompanied the question with a photo of a gentleman leading a Communion service while wearing a vestment that looked very much like a deacon’s stole over his civilian suit and tie. There was also a second extraordinary minister of holy Communion in the photo similarly attired. Based on the picture, I cannot affirm if this is a practice in the entire country, a single diocese or even a single parish. I will limit my answer to what was in the photo without making any suppositions as to the extension of the practice. With respect to this the instruction “Redemptionis Sacramentum” says the following regarding the use of lay pastoral assistants: “147. When the Church’s needs require it, however, if sacred ministers are lacking, lay members of Christ’s faithful may supply for certain liturgical offices according to the norm of law. Such faithful are called and appointed to carry out certain functions, whether of greater or lesser weight, sustained by the Lord’s grace. Many of the lay Christian faithful have already contributed eagerly to this service and still do so, especially in missionary areas where the Church is still of small dimensions or is experiencing conditions of persecution, but also in areas affected by a shortage of Priests and Deacons. “149. More recently, in some dioceses long since evangelized, members of Christ’s lay faithful have been appointed as ‘pastoral assistants,’ and among them many have undoubtedly served the good of the Church by providing assistance to the Bishop, Priests and Deacons in the carrying out of their pastoral activity. Let care be taken, however, lest the delineation of this function be assimilated too closely to the form of pastoral ministry that belongs to clerics. That is to say, attention should be paid to ensuring that ‘pastoral assistants’ do not take upon themselves what is proper to the ministry of the sacred ministers. “150. The activity of a pastoral assistant should be directed to facilitating the ministry of Priests and Deacons, to ensuring that vocations to the Priesthood and Diaconate are awakened and that lay members of Christ’s faithful in each community are carefully trained for the various liturgical functions, in keeping with the variety of charisms and in accordance with the norm of law. “151. Only out of true necessity is there to be recourse to the assistance of extraordinary ministers in the celebration of the Liturgy. Such recourse is not intended for the sake of a fuller participation of the laity but rather, by its very nature, is supplementary and provisional. Furthermore, when recourse is had out of necessity to the functions of extraordinary ministers, special urgent prayers of intercession should be multiplied that the Lord may soon send a Priest for the service of the community and raise up an abundance of vocations to sacred Orders. “152. These purely supplementary functions must not be an occasion for disfiguring the very ministry of Priests, in such a way that the latter neglect the celebration of Holy Mass for the people for whom they are responsible, or their personal care of the sick, or the baptism of children, or assistance at weddings or the celebration of Christian funerals, matters which pertain in the first place to Priests assisted by Deacons. It must therefore never be the case that in parishes Priests alternate indiscriminately in shifts of pastoral service with Deacons or laypersons, thus confusing what is specific to each. “153. Furthermore, it is never licit for laypersons to assume the role or the vesture of a Priest or a Deacon or other clothing similar to such vesture.” Therefore, the vesture similar to the deacon’s stole found in our photo would certainly violate the norm given in No. 153.
He has more to say on the subject. Read it all.
UPDATE: An astute reader points out that Vietnam is a communist country. There may possibly be legal restrictions that limit how deacons can vest.