Right now I am listening to a talk on youtube which starts with the declaration "of course we all know truth is a relative notion".

There are certainly some directions in philosophy which accept this statement, and certainly there are some others which are based on the presumption that, to the contrary, there is absolute truth. There might be still some others which are undecided on this particular question.

Does somebody know whether there is an accepted classification of alternative philosophical doctrines along this splitting?

I tried Wikipedia; the page about truth is huge, it contains lots of different subdivisions. Its contents is like this

1 Definition and etymology  

2 Major theories

2.1 Substantive theories

2.1.1 Correspondence theory  

2.1.2 Coherence theory  

2.1.3 Constructivist theory  

2.1.4 Consensus theory  

2.1.5 Pragmatic theory

2.2 Minimalist (deflationary) theories2.2.1 Performative theory of truth  

2.2.2 Redundancy and related theories  

2.2.3 Philosophical skepticism

2.3 Pluralist theories  

2.4 Most believed theories
3 Formal theories
3.1 Truth in logic  

3.2 Truth in mathematics  

3.3 Tarski's semantic theory of truth  

3.4 Kripke's semantic theory of truth  

3.5 Revision theory of truth

4 Folk beliefs about truth  

5 Notable views
5.1 Ancient history  

5.2 Middle Ages
5.2.1 Avicenna (980–1037)  

5.2.2 Aquinas (1225–1274)  

5.2.3 Changing concepts of truth in the Middle Ages

5.3 Modern age
5.3.1 Kant (1724–1804)  

5.3.2 Hegel (1770–1831)  

5.3.3 Schopenhauer (1788–1860)  

5.3.4 Kierkegaard (1813–1855)  

5.3.5 Nietzsche (1844–1900)  

5.3.6 Heidegger (1889–1976)  

5.3.7 Whitehead (1861–1947)  

5.3.8 Peirce (1839–1914)  

5.3.9 Nishida (1870–1945)  

5.3.10 Fromm (1900–1980)  

5.3.11 Foucault (1926–1984)  

5.3.12 Baudrillard (1929–2007)

6 In medicine and psychiatry  

7 See also
7.1 Other theorists

8 Notes  

9 References  

10 External links

As you see there are very many subdivisions here, I mean something coarser than that, not depending on some particular theory but rather on whether truth is considered relative, absolute or undecided.

I also tried "Absolute truth" on Wikipedia, this carries you to the page on [Universality (philosophy)](https://en.wikipedia.org/wiki/Universality_(philosophy)). There I could find something closer to what I seek, e. g. the paragraph "Universality in logic" says

> 
> In logic, or the consideration of valid arguments, a proposition is said to have universality if it can be conceived as being true in all possible contexts without creating a contradiction. Some philosophers have referred to such propositions as universalizable. A truth is considered to be universal if it is logically valid (logical) in and also beyond all times and places. Hence a universal truth is considered logically to transcend the state of the physical universe, whose order is derived from such truths. In this case, such a truth is seen as eternal or as absolute. The patterns and relations expressed by mathematics in ways that are consistent with the fields of logic and mathematics are typically considered truths of universal scope. This is not to say that universality is limited to mathematics, since it is also used in philosophy, theology, and other pursuits.
> 
> 
> The relativist conception denies the existence of some or all universal truths, particularly ethical ones (as moral relativism). Though usage of the word truth has various domains of application, relativism does not necessarily apply to all of them.
> 
> 
> 

and the paragraph "Universality in metaphysics" contains, in particular, the passage

> 
> Universal truth is regarded as ontic, i.e. expressing the order of being itself. A universal truth is epistemic only to the extent that its ontic expression is apprehended or discerned in a veridical way, which cannot affect its being in any case. Most ontological frameworks do not consider classes to be universals, although some prominent philosophers, such as John Bigelow, do.
> 
> 
> 

I feel like these hold the key but still do not understand them well enough. Should one say "universalism" and "relativism" with respect to truth?

To summarize: if I want to read about prominent philosophers arguing that truth is a relative notion, how to find out which ones are these, or under what heading are they gathered? The same about philosophers arguing that there is absolute truth - what is the umbrella term that collects them together?