diff --git a/NewCaps/WhatCouldGoWrong.md b/NewCaps/WhatCouldGoWrong.md
index 41205fa..bddb68e 100644
--- a/NewCaps/WhatCouldGoWrong.md
+++ b/NewCaps/WhatCouldGoWrong.md
@@ -17,7 +17,7 @@ This is about What Could Go Wrong with the "Elk Point 2" immutable file caps: <h
 |12|undeletion [3]footnote|generate matching (*R*,*T*,*U*) for a deleted file|anyone|any one file|the hash function's and cap format's second-preimage resistance on (*R*,*T*,*U*)|2^*n*+*t*+*u*^|
 |13|accidental collision|storage indices (*S1*,*T1*) and (*S2*,*T2*) collide accidentally|n/a|any two files|approximately random distribution of hash function outputs|[4]footnote|
 
-where *k* = bitlength(*K1*), *n* = bitlength(*R*), *t* = bitlength(*T*), *u* = bitlength(*U*), *d* = bitlength(*KD*), *dh* = bitlength(*Dhash*).
+where *k* = bitlength(*K1*), *n* = bitlength(*R*), *s* = bitlength(*S*), *t* = bitlength(*T*), *u* = bitlength(*U*), *d* = bitlength(*KD*), *dh* = bitlength(*Dhash*).
 
 1. *shape-shifter immutable file*: creator creates more than one file matching the immutable file readcap