Complete Works of Euclid, Vol. 6 (Optics, Catoptrics, etc.)

q² — scholia of codex q written by a more recent hand in livid ink.
q³ — scholia of codex q written by a recent hand in large letters in brownish ink, negligently. Sometimes faded writing has been renewed with darker ink.
r — scholia of the Parisian codex 2345, parchment, 13th century, written partly on fols. 1—5, partly in the margin.
s — scholia of the Parisian codex 2346, paper, 15th century.
t — scholia of the Parisian codex 2373, paper, 14th century, written partly before the Elements (fol. 36^u, see app. II), partly in the margin, and partly at the end of the codex (fol. 123).
u — scholia of the Parisian codex 2762, paper, 15th century (contains, among other mathematical items, Books I—VIII of the Elements).
x — scholia of the Parisian codex 2366, paper, 16th century, fols. 198—209 (with certain computations added at the end for Books I—X).
y — scholia of the Parisian codex 2343, paper, 16th century, in the text.
p — scholia of the Parisian codex 2466, parchment, 12th century (p).
Coisl. — scholia of the Coislin codex 174.
A — scholia of the Ambrosian codex C 311 inf., paper, 15th—16th century.
m — scholia of the Venetian codex of St. Mark 309, paper, 14th century (contains Books I—II of the Elements, fols. 162—183).
n — scholia of the Venetian codex of St. Mark 300, paper, 14th century.