The main contention. It will be arguable with own premises. The Premises can prove or rebuttal this contention.
Examples:

• Real art is for society, not for profit
• The meaning of life is 42
• Ethics man did what had to be done

The owner of argument. It can be instutation, person, book, or a paper. Examples:

• On the Origin of Species
• Friedrich Nietzsche
• Piet Mondiran
• The Guardian

The source of argument. It can be a URL, a book, or a newspaper. It is important for reliability of main contention.