clarify DNSSEC in geoip-backend

	from tips by @cmouse

diff --git a/docs/markdown/authoritative/backend-geoip.md b/docs/markdown/authoritative/backend-geoip.md
index f65fdaf6d72bcfe5d55989de8410af92be05b113..7b898237f62230bdad3f29266ab6b681cd3004a4 100644 (file)
--- a/docs/markdown/authoritative/backend-geoip.md
+++ b/docs/markdown/authoritative/backend-geoip.md
@@ -36,7 +36,7 @@ options described [here](https://github.com/maxmind/geoip-api-c/blob/master/READ
 Specifies the full path of the zone configuration file to use.
 
 ### `geoip-dnssec-keydir`
-Specifies the full path of a directory that will contain DNSSEC keys.
+Specifies the full path of a directory that will contain DNSSEC keys. This option enables DNSSEC on the backend. Keys can be created/managed with `pdnutil`, and the backend stores these keys in files with key flags and active/disabled state encoded in the key filenames.
 
 ## Zonefile format
 Zone configuration file uses YAML syntax. Here is simple example. Note that the ‐ before certain keys is part of the syntax.