| PO | 1 | 0 | !zero | n | SVP64Single:EXT000-063 or `RESERVED4` |
| PO | 1 | 1 | nnnn | n | SVP64:EXT000-063 |
-Note that for the future SVP64Single Encoding (currently RESERVED) it
+Note that for the future SVP64Single Encoding (currently RESERVED3 and 4) it
is prohibited to have bits 8-31 be zero, unlike for SVP64 Vector space,
for which bits 8-31
can be zero (termed `scalar identity behaviour`). This
prohibition allows SVP64Single to share its
Encoding space with Scalar Ext232-263 and Scalar EXT300-363.
+Also that RESERVED1 and 2 are given *tentative* naming EXT200-231 and
+EXT300-363 respectively, in reality they are completely unused and
+future use may allocate entirely different naming.
+
*Architectural Resource Allocation Note: **under no circumstances** must
different Defined Words be allocated within any `EXT{z}` prefixed
or unprefixed space for a given value of `z`. Even if UnVectoriseable
| Encoding | Available bits | Scalar | Vectoriseable | SVP64Single |
|----------|----------------|--------|---------------|--------------|
|EXT000-063| 32 | yes | yes |yes |
-|EXT100-163| 64 | yes | no |no |
+|EXT100-163| 64 (?) | yes | no |no |
|EXT200-231| 56 | N/A |not applicable |not applicable|
|EXT232-263| 32 | yes | yes |yes |
|EXT300-363| 32 | yes | no |no |
Prefixed-Prefixed (96-bit) instructions are prohibited. EXT200-231 presently
remains unallocated (RESERVED) and therefore its potential is not yet defined
-(Not Applicable). Additional Sandbox Opcodes are defined as EXT254 and EXT322,
-alongside EXT022.
+(Not Applicable).
# Remapped Encoding (`RM[0:23]`)