According to the General Norms for the Liturgical Year:
A. Anniversary of the Dedication of the Cathedral Church
26. In order that the importance and dignity of the local Church may stand out with greater clarity, the anniversary of the dedication of its cathedral is to be celebrated, with the rank of a solemnity in the cathedral itself, with the rank of a feast in the other churches of the diocese, on the date on which the dedication of the church recurs. If this date is always impeded, the celebration is assigned to the nearest date open. It is desirable that in the cathedral church on the anniversary the bishop concelebrate the eucharist with the chapter of canons or the priests’ senate and with the participation of as many of the people as possible.
B. Anniversary of the Dedication of a Particular Church
27. The anniversary of a church’s dedication is celebrated with the rank of a solemnity.
Some pastors and others get skittish with going off the page in the ordo. It’s probably the first bit of info a new pastor or liturgist should get. What does a solemnity mean? It gets treated pretty much like a holy day of obligation (Gloria, three readings, Credo, Sunday psalms if it hasn’t already been moved to a Sunday) only without the obligation. I do think parishes are obligated to observe and ponder this annual observance. What about your parish? Do you observe one or both of these?