* \[**Breaking**\] Variant tags are reordered.
 * \[**Breaking**\] Variant names of certain letters are renamed and reorganized, including:
   - `a`, `g`.
   - `E`, `F`, `H`, Cyrillic Small En (`н`).
   - `K`, `k`, Cyrillic Ka (`К` and `к`).
   - `L`
   - Upper Gamma (`Γ`).
   - Cyrillic Ze (`З` and `з`).
 * \[**Breaking**\] Variant selector of Cyrillic Ya (`Я` / `я`) are detached from `R`.
 
 * Add characters:
   - All remaining letters in Cyrillic block, including:
     - Cyrillic Iotified E (`U+0464`, `U+0465`).
     - Cyrillic Omega (`U+0460`, `U+0461`), Ot (`U+047E`, `U+047F`).
     - Cyrillic Psi (`U+0470`, `U+0471`).
     - Cyrillic Broad On (`U+047A`, `U+047B`).
     - Cyrillic combining Dasia (`U+0485`), Psili (`U+0486`), Pokrytie (`U+0478`).
     - Cyrillic Ornate Omega (`U+047C`, `U+047D`).
     - Cyrillic Koppa (`U+0480`, `U+0481`).
     - Cyrillic Semi-soft Sign (`U+048C`, `U+048D`).
     - Cyrillic Er with Tick (`U+048E`, `U+048F`).
     - Cyrillic tailed Short I (`U+048A`, `U+048B`), tailed El (`U+04C5`, `U+04C6`), railed En (`U+04C9`, `U+04CA`), tailed Em (`U+04CD`, `U+04CE`).
     - Cyrillic Ka with Vertical Stroke (`U+049C`, `U+049D`).
     - Cyrillic Ka with Stroke (`U+049E`, `U+049F`).
     - Cyrillic Pe with Middle Hook (`U+04A6`, `U+04A7`).
     - Cyrillic Abkhasian Ha (`U+04A8`, `U+04A9`).
     - Cyrillic Te-Tse (`U+04B4`, `U+04B5`).
     - Cyrillic Abkhazian Che (`U+04BC` ... `U+04BF`).
     - Cyrillic Ka with Hook (`U+04C3`, `U+04C4`).
     - Cyrillic Ghe with Stroke and Hook (`U+04FA`, `U+04FB`).
     - Cyrillic Ha with Hook (`U+04FC`, `U+04FD`).
     - Cyrillic Ha with Stroke (`U+04FE`, `U+04FF`).
   - Extended Cyrillic letters, including:
     - Cyrillic Reversed Ze (`U+0510`, `U+0511`).
     - Cyrillic El with Hook (`U+0512`, `U+0513`).
     - Cyrillic Pe with Descender (`U+0524`, `U+0525`).
     - Cyrillic Shha with Descender (`U+0526`, `U+0527`).
     - Cyrillic El with Descender (`U+052E`, `U+052F`).
     - Broad Omega (`U+A64C`, `U+A64D`).
   - Low asterisk (`U+204E`) and double asterisk (`U+2051`).
   - Turned Sans-serif Capital L (`U+2142`).
   - Turned Sans-serif Capital Y (`U+2144`).
   - Measured Angle (`U+2221`).
   - Spherical Angle (`U+2222`).
   - Homothetic (`U+223B`).
   - Sine Wave (`U+223F`).
   - Wreath Product (`U+2240`).
   - Between Symbol (`U+226C`).
   - Intercalate Symbol (`U+22BA`).
   - Right Angle with Arc (`U+22BE`).
   - Element Of with Overbar (`U+22F6`).
   - Small Element Of with Overbar (`U+22F7`).
   - Contains with Overbar (`U+22FD`).
   - Small Contains with Overbar (`U+22FE`).
   - Helm symbol (`U+2388`).
   - Heavy Black Heart (`U+2764`) (#920).
   - Squared Three D ... Squared VOD (`U+1F19B` ... `U+1F1AC`).
 * Add variants and stylistic sets:
   - Add tailed variants for Cyrillic El, En, Che, Yery and Ya (#972).
   - Add more serifed variants for `K`, `k`, `n`, Cyrillic Ka (`К` and `к`) and Cyrillic Ef (`ф`) to better reproduce PT Mono (#986).
   - Add top-left serifed variant for `m` (#1052).
   - Add SS18 to represent Input Mono (#990).
 * Fixes of variant selector application on derived letters or letter forms, including:
   - Cyrillic En (#1006).
   - Small U with Retroflex Hook (`U+1D99`) and Capital T with Retroflex Hook (`U+01AE`) (#1008).
   - Derivatives of Latin Small Letter L (#1015).
   - Latin Small Ligature Fi (`U+FB01`), Latin Small Ligature Fl (`U+FB02`) (#1015).
   - Latin Small Letter Ue (`U+1D6B`) (#1022).
   - Latin Capital Letter AE (`U+00C6`), Latin Capital Letter OE (`U+0152`) and derivatives (#1031).
   - Polytonic Greek letters with dual-diacritics (#1031).
   - Latin Capital B with Stroke (`U+0243`) and derivatives (#1033).
   - Latin Capital Letter F With Hook (`U+0191`) (#1038).
   - Latin Capital Letter K With Hook (`U+0198`), Latin Small Letter K with Hook (`U+0199`) (#1042).
   - Naira Sign (`U+20A6`) (#1045).
   - Greek Lunate Sigma (`U+03F9`) and derivatives (#1046).
   - P with Hook (`U+01A4`), Ruble sign (`U+20BD`) (#1047).
   - Yr (`U+01A6`), R-rotunda (`U+A75A`, `U+A75B`) (#1049).
   - Hwair (`U+01F6`), Cyrillic Capital Nje (`U+040A`) (#1059).
   - Cyrillic Izhitsa (`U+0474`) (#1061).
   - Latin Capital Letter W with Hook (`U+2C72`), Latin Small Letter W with Hook (`U+2C73`) (#1062).
   - Latin Capital Letter Z with Swash Tail (`U+2C7F`), Latin Small Letter Z with Swash Tail (`U+0240`) (#1064).
 * Fix incorrect or inconsistent serifs for Slab, including:
   - Cyrillic Small Capital El (`U+1D2B`) (#1014).
   - Latin Capital Reversed E (`U+018E`) and Modifier Capital Reversed E (`U+1D32`) (#1016).
   - Modifier Cyrillic En (`U+1D78`) under Italic (#1017).
   - Turned Sans-Serif Capital G (`U+2141`) (#1019).
   - Micro Sign (`U+00B5`) (#1025).
   - All mathematical sans-serif letters under any CV/SS application (#1030).
 * Geometry fixes:
   - Fix misplaced descender on Cyrillic Small Letter Te With Descender (`U+04AD`) (#1005).
   - Fix gap in the curly variant of R-rotunda (`U+A75A`, `U+A75B`) (#1012).
   - Fix incorrect shape of Modifier Letter Capital H with Stroke (`U+A7F8`) (#1024).
   - Fix shape of Copyleft Symbol (`U+1F12F`) (#1034).
   - Fix incorrect mapping of Greek Small Reversed Lunate Sigma Symbol (`U+037B`) and Greek Capital Reversed Lunate Sigma Symbol (`U+03FD`) (#1036).
   - Fix incorrect shape of Symbol For Device Control One (`U+2411`) (#1037).
   - Fix incorrect glyph shape mapping of Up Right Diagonal Ellipsis (`U+22F0`) and Down Right Diagonal Ellipsis (`U+22F1`) (#1039).
   - Fix missing dot on Modifier Letter Small I With Stroke (`U+1DA4`) (#1043).
   - Fix incorrect slope of Circled Italic Latin Capital C (`U+1F12B`) and Circled Italic Latin Capital R (`U+1F12C`) (#1051).
 * Geometry refinements:
   - Balance stroke width of curly W/w in bold weights (#1011).
   - Make lowercase Cyrillic Em wider (Aile/Etoile) (#1028).
   - Make combining parentheses more significant (#1032).
   - Increase visibility of Cyrillic Descender (#1018).
   - Increase oval size of Cyrillic Be (`U+0431`) (#1023).