Being a child of the 80s, I remember well the periodic confrontations between the US Navy and Libya in the Gulf of Sidra. The US has a policy of challenging limits placed on navigation which are excessive and not in accord with international law. Goofball Muammar Gaddafi had claimed the Gulf of Sidra as territorial waters, the US challenged that claim, and Libya lost several aircraft and ships over the decade.
Why am I talking about this? Because this is how I view certain liturgical actions. Not long ago, one of my deacons asked why we don't distribute Holy Communion under both species at our 6:00 p. m. Mass even when one of the deacons is present. I told him that it was to make clear that Holy Communion under one species is perfectly valid. (Last year during the Swine Flu scare, many of my parishioners opined that they felt they hadn't received all of Jesus if they only received the Host: catechetical failure!) Let's be clear on this, a requirement for the laity to receive under both species is the heresy of Utraquism.
Other liturgical practices, not required but laudable, can also come under Freedom of Navigation. Use of the Confiteor, wearing a cassock, biretta, zucchetto, maniple, using the Roman Canon,using black vestments, and celebrating the Extraordinary Form of the Mass all come to mind. It is important that these optional things that drive the liturgical establishment be done in order to demonstrate that they can be done. (I could argue from other points that they should be done.) A right which is not exercised is a right soon lost.