diff --git a/test/programs/edn.flan b/test/programs/edn.flan
index d54739a..a1d7b2c 100644
--- a/test/programs/edn.flan
+++ b/test/programs/edn.flan
@@ -145,7 +145,9 @@
   (dump "-1 +2 0")               ; the signs are part of the number
   (dump "1.5 -2.5e3 .5")         ; f, and a leading dot is a float
   (dump "true false nil")        ; b b n — and not three symbols
-  (dump "foo foo/bar -")         ; `-` alone is a symbol; `foo/bar` is NOT a ratio
+  ;; `-` alone is a symbol, `foo/bar` is NOT a ratio, and the uppercase half
+  ;; of the alphabet test is only exercised by a name that has one in it.
+  (dump "foo Enemy/Goblin -")
   (dump ":a :foo/bar")           ; k, text without the colon
   (newline)
 
@@ -215,6 +217,11 @@
   (refusal "[1 2}")              ; the wrong closer
   (refusal "]")                  ; a closer with nothing open
   (refusal "[1 2")               ; end of input with something still open
+  ;; 33 opening brackets against a 32-deep stack. The error message is the
+  ;; least of what this checks: a `>` where the guard needs `>=` writes one
+  ;; past the end of a fixed array, and the answer is a bounds trap rather
+  ;; than a wrong message. The offset is the 33rd bracket.
+  (refusal "[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[")
   (newline)
 
   ;; ── The struct reader ─────────────────────────────────────────────
diff --git a/test/test_acceptance.ml b/test/test_acceptance.ml
index ccfd5cf..9ea3694 100644
--- a/test/test_acceptance.ml
+++ b/test/test_acceptance.ml
@@ -404,7 +404,7 @@ let () =
 i<-1>i<+2>i<0>
 f<1.5>f<-2.5e3>f<.5>
 b<true>b<false>n<nil>
-y<foo>y<foo/bar>y<->
+y<foo>y<Enemy/Goblin>y<->
 k<a>k<foo/bar>
 
 [<>i<1>]<>
@@ -452,6 +452,7 @@ s<a b>
 4 unbalanced: this closing delimiter does not match the one that is open
 0 unbalanced: this closing delimiter does not match the one that is open
 4 unbalanced: this closing delimiter does not match the one that is open
+32 nesting is too deep: the balance stack is a fixed array and it is full
 
 [goblin] hp=12 speed=1.5 boss=no
 [dragon] hp=40 speed=0 boss=yes
diff --git a/vendor/edn/edn.flan b/vendor/edn/edn.flan
index eb41be4..72df9df 100644
--- a/vendor/edn/edn.flan
+++ b/vendor/edn/edn.flan
@@ -53,6 +53,17 @@
 ;;;;                     a byte once anything is non-ASCII, and there is no
 ;;;;                     code point type.
 ;;;;
+;;;; ── One place this is not EDN, on the record ────────────────────────
+;;;;
+;;;; `.5` is a float here. In EDN a number must begin with a digit and `.` is
+;;;; a legal symbol-start byte, so strictly `.5` is the *symbol* `.5` — which
+;;;; makes this a reinterpretation of a legal token and not an extension, and
+;;;; therefore the kind of thing that gets written down rather than discovered.
+;;;; It is this way because number-start? runs before the symbol case and
+;;;; parse-f64 accepts a leading dot; a caller who needs the symbol reading
+;;;; should not be writing `.5` at all. `-`, by contrast, is a symbol, because
+;;;; number-start? requires a digit after the sign.
+;;;;
 ;;;; ── Errors ──────────────────────────────────────────────────────────
 ;;;;
 ;;;; On the cursor, not in the return type. `next` answers a Token whose kind
@@ -221,6 +232,10 @@
       (= b \/)))
 
 ;; ── Internal helpers ────────────────────────────────────────────────
+;;
+;; "Internal" by intent and not by enforcement: a package has no visibility
+;; yet, so edn/scan-atom and edn/push-open are as callable as edn/next is.
+;; Nothing below is part of the API and none of it will keep its shape.
 
 (defn at-end? [c (Ptr Cursor)] bool
   (>= (.pos c) (len (.src c))))