clarify

docs/source/index.rst

@@ -70,7 +70,7 @@ Language features
 - Variable data types include signed and unsigned bytes and words, arrays, strings.
 - Floating point math also supported if the target system provides floating point library routines (C64 and Cx16 both do).
 - Strings can contain escaped characters but also many symbols directly if they have a PETSCII equivalent, such as "♠♥♣♦π▚●○╳". Characters like ^, _, \\, {, } and | are also accepted and converted to the closest PETSCII equivalents.
-- High-level code optimizations, such as const-folding, expression and statement simplifications/rewriting.
+- High-level code optimizations, such as const-folding (zero-allocation constants that are optimized away in expressions), expression and statement simplifications/rewriting.
 - Many built-in functions, such as ``sin``, ``cos``, ``abs``, ``sqrt``, ``msb``, ``rol``, ``ror``, ``sort`` and ``reverse``
 - Programs can be run multiple times without reloading because of automatic variable (re)initializations.
 - Supports the sixteen 'virtual' 16-bit registers R0 .. R15 from the Commander X16, also on the other machines.

docs/source/programming.rst

@@ -400,9 +400,9 @@ library function instead)
 Special types: const and memory-mapped
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-When using ``const``, the value of the 'variable' can no longer be changed.
+When using ``const``, the value of the 'variable' cannot be changed; it has become a compile-time constant value instead.
 You'll have to specify the initial value expression. This value is then used
-by the compiler everywhere you refer to the constant (and no storage is allocated
+by the compiler everywhere you refer to the constant (and no memory is allocated
 for the constant itself). This is only valid for the simple numeric types (byte, word, float).
 
 When using ``&`` (the address-of operator but now applied to a datatype), the variable will point to specific location in memory,