...So I came across the CJK Working Group's proposal (topic 19 in L2/25-186, https://www.unicode.org/L2/L2025/25186-cjk-unihan-wg-utc184.pdf) to move the [Small] Seal block's proposed Unicode 18.0 allocation to the beginning of Plane 4 (in order to free up the rest of the TIP for additional CJK ideographs) and formally designate Plane 4 as the Archaic Ideographic Plane (AIP), to be used for the seal script (and presumably also for the other Old Hanzi scripts - bronze, oracle bone, etc. - when *they* eventually get encoded).
I also came across L2/25-187 ( https://www.unicode.org/L2/L2025/25187-sew-recommendations-utc184.pdf), in section 4.1 of which the Script Encoding Working Group recommended that the CJK Working Group's proposal be rejected and that the Seal block merely be pushed down to the end of the TIP (the option that was ultimately chosen), in part because "The proposed Archaic Ideographic Plane does not account for Tangut and Jurchen being put in Plane 1." Why *were* the siniform ideographic scripts Tangut, Khitan Small Script, and (when Unicode 18.0 gets released) Jurchen placed in the SMP (where they account in large part for why there's so little remaining SMP space without at least a tentative allocation)? Were the Ideographic Planes only ever intended for *CJK* ideographs (but then why was the TIP originally intended exclusively for Old Hanzi, with at least one Old Hanzi script having held on in the TIP ever since, even as the TIP's started to fill up with CJK ideographs)? Or were they intended as general-purpose planes for large ideographic scripts (but then, again, why have several such scripts been squeezed into the SMP)? And, regardless of where Seal itself ends up, won't the remaining Old Hanzi scripts spill over onto Plane 4 *anyway*, given that there're evidently enough CJK ideographs proposed for encoding to fill up the entirety of the TIP except for the Seal portion right at the end? - Vikki McDonough 🏳️⚧️
