These three sections conclude the introduction to the celebration of viaticum. A reminder these are not obscure, minor documents. These texts of the Pastoral Care rites, sections 175-188, are to viaticum as the GIRM is to the celebration of Mass.
Ever practical, when Mass with viaticum cannot be celebrated, there is a fallback option:
186. Although viaticum celebrated in the context of the full eucharistic celebration is always preferable, when it is not possible the rite for viaticum outside Mass is appropriate. This rite includes some of the elements of the Mass, especially a brief liturgy of the word. Depending on the circumstances and the condition of the dying person, this rite should also be a communal celebration. Every effort should be made to involve the dying person, family, friends, and members of the local community in the planning and celebration. The manner of celebration and the elements of the rite which are used should be accommodated to those present and the nearness of death.
When might viaticum outside of Mass be celebrated? If a priest is unavailable. If the dying person is unable to physically tolerate a longer celebration. If the surroundings and circumstances cannot provide for a reverent or appropriate celebration of Mass. Even if any of these conditions are met, two vital factors cannot be ignored: the importance of planning, and the participation of the community (however community is defined).
187. If the dying person wishes to celebrate the sacrament of penance and this cannot take place during a previous visit, it should be celebrated before the rite of viaticum begins, especially if others are present. Alternately, it may be celebrated during the rite of viaticum, replacing the penitential rite. At the discretion of the priest, the apostolic pardon may be added after the penitential rite or after the sacrament of penance.
The possibilities are given in order of preference: penance on a previous visit, penance before viaticum liturgy, penance in place of the penitential rite. Note this is not a choice of equals.
188. An abbreviated liturgy of the word, ordinarily consisting of a single biblical reading, gives the minister an opportunity to explain the word of God in relation to viaticum. The sacrament should be described as the sacred food which strengthens the Christian for the passage through death to life in sure hope of the resurrection.
At minimum, there is one reading. Note another emphasis on the Eucharist as meal, as spiritual sustenance for the challenges the dying person (and his or her community) will confront.
In the next few posts, we’ll browse through the rubrics and texts, comparing and contrasting the two forms of viaticum, within Mass (PCS 189-196) and outside of it (197-211). We don’t have much commentary on these posts, my friends, do we? It’s not a very controversial topic, but one important to review, study, and consider in a pastoral liturgy setting–not to mention the time of one’s own death or death of a loved one.
Catholic Sensibility 
I find it interesting to see the possibility of the Apostolic Pardon being pronounced in the context of liturgy.
For those not aware of it, the Apostolic Pardon, along with the indulgence “in articulo mortis”, is the greatest of the plenary indulgences. A recent discussion:
http://wdtprs.com/blog/2008/09/the-apostolic-pardon-fathers-do-you-know-it/
I thought about commenting on this, but it will come up when we cover PCS 195, in which the apostolic pardon is added at the conclusion of Mass, or PCS 201, when it precedes the liturgy of the word at viaticum outside of Mass.