From 7137b5770384a9de3f44b8cb961ae81e161678c8 Mon Sep 17 00:00:00 2001
From: James Bonfield <jkb@sanger.ac.uk>
Date: Wed, 16 Jun 2021 09:47:24 +0100
Subject: [PATCH] Be more explicit on phred scale definition.

---
 SAMv1.tex | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/SAMv1.tex b/SAMv1.tex
index 2998e9c79..cd89c5f42 100644
--- a/SAMv1.tex
+++ b/SAMv1.tex
@@ -167,8 +167,9 @@ \subsection{Terminologies and Concepts}
   between the 3rd and the 7th bases inclusive is $[2,7)$. The BAM, BCFv2, BED,
   and PSL formats are using the 0-based coordinate system.
 
-\item[Phred scale] Given a probability $0<p\le 1$, the phred scale of $p$
-  equals $-10\log_{10}p$, rounded to the closest integer.
+\item[Phred scale] Given a probability $0<p\le 1$ of an erroneous
+  call, the phred scale of $p$ equals $-10\log_{10}p$, rounded to the
+  closest integer.
 
 \end{description}