The meaning of the underlined 'rubric'

the meaning of the underlined 'rubric'

The passage below comes from a web page as follows.

https://www.farnamstreetblog.com/2016/03/the-false-allure-of-a-natural-state-of-man/

It is certainly true to say that premodern agriculturists tended to be theists, but it does not teach us much about the particulars. The generic rubric‘theists’ covers Jewish rabbis from eighteenth-century Poland, witch-burning Puritans from seventeenth-century Massachusetts, Aztec priests from fifteenth-century Mexico, Sufi mystics from twelfth-century Iran, tenth-century Viking warriors, second-century Roman legionnaires, and first­century Chinese bureaucrats. Each of these viewed the others’ beliefs and practices as weird and heretical.

In this passage I cannot figure out the meaning of the underlined 'rubric' in this context. FreeDictionary presented a number of meaning in a noun and a adjective but I find none of them fit in the passage.

(The situation in which 'rubric' has gotten into gives me the impression that it means 'list of something'. But I am not sure.)

http://www.thefreedictionary.com/rubric
n.
1. a title, heading, or the like, in a manuscript, statute, etc., written or printed in red or otherwise distinguished from the rest of the text.
2. a direction for the conduct of divine service or the administration of the sacraments, inserted in liturgical books.
3. any established rule of conduct or procedure.
4. a class or category.
5. an explanatory comment; gloss.
6. Archaic. red ocher.
adj.
7. written or marked in red.
8. Archaic. red; ruddy.

Help me.
Regards.