One of these days I'll collect those classifications and see on how many of them I fit. I would guess about a half dozen, at a minimum.
Too bad that most people will just barely tell agnosticism from atheism, let alone understand what apatheism or ignosticism are.
Ignosticism is particularly difficult because of the prefix i/ig- being used in a particular sense of negation. With ignorance, there is a lack of knowledge because of the natural state of being constantly exposed to new knowledge, as opposed to just willfully accepting ignorance, which is closer to idiocy. Ignosticism suggests that our knowledge of God will never be adequate, it seems to me, so technically an ignostic could be atheist or theist, similar to agnosticism (which is described further down)
Apatheism is also admittedly underground, because so few people label themselves as such. Denis Diderot was the first to coin the term to my knowledge and he is only so well known in circles of philosophy scholarship, etc. But then many apologeticists would suggest apatheism could apply even to people who nominally label themselves Christian, since they behave as if God doesn't exist or doesn't matter even if it does exist, so the extent of apatheism is nearly as difficult as agnosticism or atheism. Antitheism and contratheism are at least more specific so as not to be as confused. Though maltheism occurs to me as I read it in another thread on atheism, so the extent of terms only expands further to cover even people who may actually believe in God, but are a minority that either hate it or disregard it as important to human affairs, ala apatheists or deists.
But agnosticism and atheism can be distinguished easier than one might think with the obvious four square model, where atheism and theism take up the top two squares and agnosticism and gnosticism the far left two squares. Then you just follow the pattern: agnostic atheists and theists exist, as well as the gnostic atheists (contratheists or antitheists moreso) and theists. I also believe Richard Dawkins posited a spectrum a 7 degrees of belief in God, ranging from absolute belief to absolute disbelief, though I am not sure of the degrees in between.