Re: [PATCH] git.txt: correct stale 'GIT_EXTERNAL_DIFF' description

diff --git a/Documentation/diff-generate-patch.txt b/Documentation/diff-generate-patch.txt
index e8ed6470fb..b10ff4caa6 100644
--- a/Documentation/diff-generate-patch.txt
+++ b/Documentation/diff-generate-patch.txt

@@ -10,7 +10,8 @@ linkgit:git-diff-tree[1], or
 linkgit:git-diff-files[1]
 with the `-p` option produces patch text.
 You can customize the creation of patch text via the
-`GIT_EXTERNAL_DIFF` and the `GIT_DIFF_OPTS` environment variables.
+`GIT_EXTERNAL_DIFF` and the `GIT_DIFF_OPTS` environment variables
+(see linkgit:git[1]).
 
 What the -p option produces is slightly different from the traditional
 diff format:

diff --git a/Documentation/git.txt b/Documentation/git.txt
index 2fc92586b5..98bdf0983c 100644
--- a/Documentation/git.txt
+++ b/Documentation/git.txt

@@ -551,8 +551,9 @@ Git Diffs
 
 `GIT_EXTERNAL_DIFF`::
 	When the environment variable `GIT_EXTERNAL_DIFF` is set, the
-	program named by it is called, instead of the diff invocation
-	described above.  For a path that is added, removed, or modified,
+	program named by it is called to generate diffs, and Git
+	does not use its builtin diff machinery.
+	For a path that is added, removed, or modified,
 	`GIT_EXTERNAL_DIFF` is called with 7 parameters: