Sadly, heresy refers to viewpoints at odds with those in power within religious establishments, such as a state church, whether in Italy or England.
An interesting charge is "Heresy against Doctrine" which to say a group adopts a particular view, then alternate interpretations are claimed to be "Heresy."
Lets list a few:
1) Omniscience can only mean knowing everything imaginable, rather than knowing only what has been chosen to know, i.e. Inherent Omniscience.
2) Total Spiritual Inability means the lost are unable to understand any spiritual thing of the Spirit of God, rather than having the ability to understand spiritual milk, but not spiritual solid food.
3) Monotheism rather than God is the Trinity.
4) God created everything less than 7000 years ago (YEC) rather than we do not know when everything was created.
5) The KJV is the only English bible to be used, all others are perversions of God's word.
6) Born anew believers obtained the righteousness of God by imputation, rather than by the washing of regeneration.