Two kinds of obligation referring to subject matter are legal obligations, which are enforceable by law and can result in penalties or consequences for non-compliance, and moral obligations, which are based on ethical principles or personal beliefs and may not have legal consequences but can impact one's reputation or relationships.
The subject-matter of phonetics.
The subject matter is what the book is about. So if you have a book on, say, Winston Churchill, he is the subject matter.
Subject matter is what an art work has been created about. For example if you were to have a painting of a cow, then the subject matter is a cow.
how do the paintings compare in terms of their subject matter
The subject in the poem "Does It Matter" by Siegfried Sassoon is "you."
everything has matter
When you look "deep into the matter," you do not take the subject matter at face value. Instead, you examine the subject matter upon an empirical basis. That is, you apply the scientific method to the subject matter.
The learner learns the subject matter
A subject matter expert in the hazards or recovery activities underway within the incident site.
Subject matter, theme, matter in hand, field, subject...
Iconography is the study of the subject matter of art.
The subject matter is a dove of peace! It is a symbol for peace.