diff --git a/docs/index.rst b/docs/index.rst
index 1586a0f..549e3c8 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -12,6 +12,7 @@ RTFD
    public/bcompare/index
    public/bind9/index
    public/c/index
+   public/certbot/index
    public/connect/index
    public/coreutils/index
    public/curl/index
diff --git a/docs/public/certbot/index.rst b/docs/public/certbot/index.rst
new file mode 100644
index 0000000..51f34aa
--- /dev/null
+++ b/docs/public/certbot/index.rst
@@ -0,0 +1,22 @@
+certbot
+=======
+
+DNS certificate
+---------------
+
+.. code:: shell
+
+ mkdir tmp
+ certbot \
+ --config-dir tmp \
+ --logs-dir tmp \
+ --work-dir tmp \
+ certonly \
+ --agree-tos \
+ --manual \
+ --manual-public-ip-logging-ok \
+ --no-eff-email \
+ --preferred-challenges dns \
+ --email acme@domain.tld \
+ --domains domain.tld,*.domain.tld \
+ --csr file.csr