·    Do not confuse with tu:

o si has three small non-touching dots in a row.

o tu has cross-hatched area (with optional face).

Sub-variants (1)

·    Only variant:

o Left: flint, with:

§ Reinforcement of the ceiling and (optionally) left wall (and even more optionally, right wall)).

§ A row of three or more non-touching small dots (canonically three).

o Middle: circle with reinforcement on right and (optionally) top and bottom.

o Right: left and right scroll, each with protector.

·    There is a rare variant, featuring a rat’s head.

·    Sergei Vepretskii: this [= the “rat head” glyph] is in fact a very rare form of si, making YAX Lintel 10 D6 usij uchit (u)ch’ab = “the child of”. This is cited in Kettunen&Helmke-RoB.p34.pdfp34.fig65i.

·    MHD statistics. A search in “Classic - Blocks” with:

o “blcodes contains 3M6” gives 377 hits:

§ 3M6 is both the stylized and the “beetle” variant. MHD doesn’t distinguish the stylized variant from the “beetle” variant.

§ 377 hits is overcounting slightly, as the “beetle” variant is also included in this count. Nevertheless, it doesn’t overcount too much, as the “beetle” variant is known to be quite rare also, anyway.

o “blcodes contains APC” gives 15 hits:

§ This too might be overcounting, because quite a number of these hits are APC? rather than pure APC.

In any case, it confirms Sergei’s explanation that the “rat head” variant is quite rare.