[PATCH/RFC 4/5] document the new "unset.variable" variable

[Tanay Abhra <tanayabh@gmail.com>]

Helped-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Tanay Abhra <tanayabh@gmail.com>
---
 Documentation/config.txt | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/Documentation/config.txt b/Documentation/config.txt
index 3b5b24a..7f36d35 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -2382,6 +2382,18 @@ transfer.unpackLimit::
 	not set, the value of this variable is used instead.
 	The default value is 100.
 
+unset.variable::
+	This variable can be used to unset previously set variables
+	which had been already declared in files of lower priority
+	or declared before in the same file. It does not unset
+	matching variables declared after its position in the file
+	or in files of higher priority. It can be used to unset
+	pesky variables declared in files which the user might not
+	be able to open due to not having the required security
+	privileges, for example, system wide configuration file
+	`/etc/gitconfig` which may be accessible to the system
+	administrator only.
+
 uploadarchive.allowUnreachable::
 	If true, allow clients to use `git archive --remote` to request
 	any tree, whether reachable from the ref tips or not. See the
-- 
1.9.0.GIT