Q: I am confused by the Table of Liturgical Days, nn. 4, 8, and 11. For example, would the feast day of the titular saint of our parish be celebrated as a solemnity, a feast or a memorial? Who determines that?
A: # 4 on the Table determines that the day that honors the titular saint of your parish ranks as a solemnity there—unless, of course, it already is one, such as the Immaculate Conception or the Sacred Heart. When you celebrate the solemnity at your parish church, Mass requires three readings drawn from the commons. You also include both the Gloria and the Creed. The Liturgy of the Hours is also affected.
#8 concerns feasts that are proper to a particular church. For example, the principal patron of your diocese, if not already on the calendar as a feast or solemnity, becomes a feast at every parish. So does the anniversary of the dedication of your cathedral. All the parishes are to treat that anniversary as a feast with special readings at Mass and a Gloria—and the proper sections of the Liturgy of the Hours.
#11 concerns proper memorials that have been designated for that diocese. For example, in my diocese, one of the earliest missionaries wrote the bishop asking permission to name the log cabin church after St. John Francis Regis. The Vatican names that French saint as a secondary patron for us, and all our parishes honor his day as a Memorial.