Here are some details of the mechanical implementation if you are curious...
The HEART_BYTE() of the cell encodes its fundamental type (e.g. BLOCK!, GROUP!, INTEGER!, whatever)
The LIFT_BYTE() thus doesn't have to encode things like "are you a void". Voidness comes from being in the 0 state (ANTIFORM_0).
#define NONQUASI_BIT 1
#define ANTIFORM_0 0 // also "QUASI" (NONQUASI_BIT is clear)
#define NOQUOTE_1 1
#define QUASIFORM_2 2
#define ONEQUOTE_NONQUASI_3 3 // non-quasiquoted state of 1 quote
#define ONEQUOTE_QUASI_4 4 // quasiquoted state of 1 quote
// ...etc
The antiforms come from this table:
https://rebol.metaeducation.com/t/which-antiforms-are-in-use/2276