I am interested in the dots used to separate the various sections of Rashi's commentary to Torah and Talmud. Are these dots found in early printed editions of Rashi or are they a later innovation?
There are two considerations in separators, one is the marker of the end of the lemma, the other is the marker of the end of the comment. Usage has not been consistent, but development may be seen. There is enough variation to suggest that a wider range may even be found in mss., but that would be another inquiry. In Rashi on the Torah, I looked at ed. Rome 1489/92 and Soncino 1487. Ed. Rome used no punctuation only spaces to separate lemmata and commentary, as well as divisions within commentary, nothing even at the end of a chapter. Soncino, OTOH, separated lemma with one dot and marked end of comment with two vertical ones or one. In Talmud, progress went from nothing after lemma to marking it. Soncino 1487 used one dot to mark end of comment. An unkown Spanish edition, ca. 1482, used two vertical dits or two horizontal ones (sometimes just one). Other printed edns. (random sampling of 16th & 17th cent., items) separated comments with two vertical dots, but did not mark end of lemmata, except for Cracow 1603 Pesahim which sometimes separated lemma with single dot. By the 18th cent., many editions separated comments with two dots and ended lemmata with single dot, e.g., Frankfurt a/M 1720, Berlin 1734, Sulsbach, 1766, and so into the 19th cent. (except that Slavuta 1817 did not mark end of lemmata). It should be noted that some editions also used spacing to separate comments. Also noteworthy is that single dots can come at top of line, bottom, and center.
(Answer provided by Dr. Jay Rovner, JTS Library's Manuscript Bibliographer.)