(The following is a summary of the relevant section inbased on Wallace 2011, The Latin alphabet and orthography and Edmondson 2015, Inscribing Roman Texts: Officinae, Layout, and Carving Techniques)
Wallace observes that
Most Latin documents, regardless of type, had very little in the way of punctuation (p. 22).
Archaic Latin. Written mostly in scriptio continua (i.e. often no word breaks or punctuation between words); sometimes, interpuncts were used between words (including two or three vertical interpuncts).
Classical Latin. Interpuncts separated words. Edmondson 2015 argues the most common form of interpuncts was triangles. He also mentions
- small squares;
- rectangles;
- arrow-heads;
- commas;
- ivy-leaves (hederae);
- circles;
- tildes etc.
Late Latin. Interpuncts for separating words became less common and were used to mark phrases.
What's really interesting about interpuncts is that they were normally added after the text was inscribed (Edmondson 2015: 127).
Indentation as well as empty space was used in longer texts to mark paragraphs, e.g in the Lyon Table.