diff --git a/proposal.txt b/proposal.txt
index 6a63ac2..1956784 100644
--- a/proposal.txt
+++ b/proposal.txt
@@ -43,6 +43,11 @@ i propose adding four bytes to the start of every rom:
  - the literal 3 bytes "uxn"
  - a fourth metadata mode byte
 
+the bytes "uxn" correspond to the instructions STA2r ADD2r JSR2r, so
+we aren't at risk of creating an ambiguity with valid uxn roms which
+previously would have worked, since a rom starting with STA2r would
+immediately crash.
+
 this proposal just covers metadata modes 0 and mode 1, but in the
 future we could have up to 254 other modes to use (though we might
 choose to forbid those later to keep things simple).
@@ -122,7 +127,7 @@ external applications might have an easier time with other formats
 of use by other uxn roms running inside varvara.
 
 the maximal "uxn1" header size (assuming all strings are maximum
-length and using an icon format of x0a3) would be 5904 bytes. while
+length and using an icon format of 0xe3) would be 5904 bytes. while
 this is substantial it is unlikely to push most rom sizes over 64k
 (the point at which working with them from within varvara becomes
 annoying). since the maximum rom data size is 65280, authors are
@@ -153,7 +158,7 @@ doesn't feel better than just limiting ourselves to ASCII (but maybe
 that's my own cultural bias speaking) and (d) sounds like total chaos.
 so my take is that inside varvara only ASCII values are likely to be
 well-supported, but for display outside varvara UTF-8 feels like the
-best option (e.g. allowing author's to write their names correctly).
+best option (e.g. allowing authors to write their names correctly).
 
 another weirder option would be to provide graphical tiles or font
 data that authors could use to encode program text. embedding a