diff --git a/html/mu_instructions.html b/html/mu_instructions.html
index b12e3f12..3988277b 100644
--- a/html/mu_instructions.html
+++ b/html/mu_instructions.html
@@ -31,10 +31,11 @@ body { font-family: monospace; color: #000000; background-color: #ffffd7; }
See http://akkartik.name/akkartik-convivial-20200607.pdf for the complete
-story. In brief: Mu is a statement-oriented language. Blocks consist of flat
-lists of instructions. Instructions can have inputs after the operation, and
-outputs to the left of a '<-'. Inputs and outputs must be variables. They can't
-include nested expressions. Variables can be literals ('n'), or live in a
+story. In brief: Mu is a memory-safe statement-oriented language where most
+statements translate to a single instruction of machine code. Blocks consist of
+flat lists of instructions. Instructions can have inputs after the operation,
+and outputs to the left of a '<-'. Inputs and outputs must be variables. They
+can't include nested expressions. Variables can be literals ('n'), or live in a
register ('var/reg') or in memory ('var') at some 'stack-offset' from the 'ebp'
register. Outputs must be registers. To modify a variable in memory, pass it in
by reference as an input. (Inputs are more precisely called 'inouts'.)
diff --git a/mu_instructions b/mu_instructions
index 4898f9a1..a7cea787 100644
--- a/mu_instructions
+++ b/mu_instructions
@@ -1,10 +1,11 @@
## Mu's instructions and their table-driven translation
See http://akkartik.name/akkartik-convivial-20200607.pdf for the complete
-story. In brief: Mu is a statement-oriented language. Blocks consist of flat
-lists of instructions. Instructions can have inputs after the operation, and
-outputs to the left of a '<-'. Inputs and outputs must be variables. They can't
-include nested expressions. Variables can be literals ('n'), or live in a
+story. In brief: Mu is a memory-safe statement-oriented language where most
+statements translate to a single instruction of machine code. Blocks consist of
+flat lists of instructions. Instructions can have inputs after the operation,
+and outputs to the left of a '<-'. Inputs and outputs must be variables. They
+can't include nested expressions. Variables can be literals ('n'), or live in a
register ('var/reg') or in memory ('var') at some 'stack-offset' from the 'ebp'
register. Outputs must be registers. To modify a variable in memory, pass it in
by reference as an input. (Inputs are more precisely called 'inouts'.)