Unicode: F751. Letter-like form.
Unicode: 2021. Alias: Esc ddg Esc. Letter-like form.
Unicode: 21D3. Infix arrow operator. x ⇓ y is by default interpreted as DoubleDownArrow[x,y]. Extensible character.
Unicode: F6E6. Alias: Esc dsa Esc.
Unicode: F6E7. Alias: Esc dsb Esc.
Unicode: F7A4. Alias: Esc dsA Esc.
Unicode: F7A5. Alias: Esc dsB Esc.
Unicode: F7A6. Alias: Esc dsC Esc.
Unicode: F7A7. Alias: Esc dsD Esc.
Unicode: F7A8. Alias: Esc dsE Esc.