·    Without a bay on the bottom left of the boulder:

o TUUN/ku-like outline, optionally with reinforced inner wall.

o Two or three indentations on the left all and left side of floor.

o Three non-touching dots in a row, diagonally; middle dot slightly larger than the other two.

o (Optionally) struts from inner wall (bold in this case) to the ceiling.

·    QRG Stela I C8:

o Has a form of jo that is quite difficult to recognize.

o Not only that, but the reading order is slightly unexpected, making it slightly more difficult to work out what is written.

o <ch’a:<jo.ja>>.<u.K’AHK’> needs to be read jo-ch’a-ja u-K’AHK’ è johch’aj uk’ahk’ = “it was drilled, the fire of …”.

·    Three-quarter circle of boulder outline, with bold inner bottom, sides, and top.

·    With a bay on the bottom left of the boulder. The bay faces outwards in the bottom left corner, also with reinforced wall (outer wall of bay, but inner wall of boulder).

·    Three non-touching dots in a triangular formation, diagonal pointing down, i.e. a “face”.

·    One and a half very slightly curved struts at the top. The phrase “one and a half struts” means one strut and one slightly curved line (alternatively, a single strut with one wall a bold wall.

·    Nickname: “Face in Renaissance Window”.

·    Stuart-ONojaw.p1.fig1: A late example of the jo syllable from the Dresden Codex.

·    Sergei Vepretskii:

o This variant was removed from some textbooks (perhaps because it is a codex glyph and from a later period).

o In the Classic period, there were ceramics in codex style (=red border and crème background), but it is uncertain to what extent these were similar to the codex glyphs of the Classic period.

o Note that the glyphs on ceramics are significantly different from the (later) codex glyphs – they are both different from the monumental glyphs but also different from one another.

·     That the glyph with a large spiral / scroll starting from the bottom left and occupying a large part of the centre is an early form of jo is given in Stuart-ANVotSk.fig5, supported by the word tzutzjoom written ²TZUTZ.<jo:ma>, with this variant of jo.

·     The earlier form has optional “horseshoes” and/or optional butterfly/bow-tie ma-like element on top.