Official Website of the – Order of the Carmelites of the Holy Face
The Palmarian Church is an example of a "Schismatic" sect.
In modern media you see the term "heretic" thrown around in religious or semi-religious context. Normally, when a religious character encounters something they don't like. Non-religious people by now equate the term heretic with anything distasteful.
But a heretic is actually a specific thing. It is a Christian (or any of the Abrahamic faiths, or whichever organized faith is claiming to the only way to God) who has supposedly turned their back on the "truth" (the highly specific teachings of said religious tradition) and either embraces another tradition is simply theologically lackadaisical.
Meanwhile someone or a group of people who are "schismatic" are technically theologically orthodox but do not recognize the original religious authority of their originating group. Hence, the Palamarians, who for all intents and purposes are Catholics (ala 1978).