diff --git a/README.md b/README.md
index 2a1d452..83f15b9 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@
 sudo python3 setup.py install
 ```
 
-### Windows (from PowerShell)
+### Windows (from PowerShell, untested)
 
   ```powershell
 & $(where.exe python).split()[0] setup.py install
@@ -19,5 +19,49 @@ sudo python3 setup.py install
 ## Usage
 
   ```bash
-remove_duplicate_imap_messages.py [--debug-level|-d CRITICAL|ERROR|WARNING|INFO|DEBUG|NOTSET] # Other parameters
+Usage: remove_duplicate_imap_messages.py [OPTIONS]
+
+Options:
+  -d, --debug-level [CRITICAL|ERROR|WARNING|INFO|DEBUG|NOTSET]
+                                  Set the debug level for the standard output.
+  -l, --log-file TEXT             File to store all debug messages.
+  -n, --dummy                     Don't do anything, just show what would be
+                                  done.
+  -s, --imap-server TEXT          IMAP server
+  -p, --imap-port INTEGER RANGE   IMAP server port  [1<=x<=65535]
+  -u, --imap-user TEXT            User name to use for the connection to the
+                                  IMAP server  [required]
+  -P, --imap-password TEXT        Password to connect to the IMAP server.
+                                  Warning! Use a configuration file to avoid
+                                  revelaing your passwords.  [required]
+  -S, --ssl BOOLEAN               Whether to use a secure connection or not.
+  -m, --mailbox TEXT              IMAP mailboxes to check. Will compare
+                                  messages between all mailboxes. Default:
+                                  INBOX
+  -m, --method [full|headers]     Method to decide messages are duplicated.
+                                  The 'full' method will check that the whole
+                                  message and headers are the same. The
+                                  'headers' method will check that selected
+                                  headers (with --header) are the same.
+  -f, --header TEXT               Fields to compare when method is 'headers'
+  --config FILE                   Read configuration from FILE.
+  --help                          Show this message and exit.
 ```
+### The 'full' method.
+This method will take all information of the message (headers, dates, recipients, sender, subject, body, ...) and create a code (SHA256 hash), if the code is the same for another message then they are consider duplicates.
+
+### The 'header' method
+This method will take only the select headers (at least one) and create a code (SHA256 hash), if the code is the same for another message then they are consider duplicates.
+Some common headers are:
+- Subject
+- Body
+- To
+- From
+- Reply-To
+And there is a RFC (Request For Comments with more) https://www.rfc-editor.org/rfc/rfc2076 but ultimately you can add any custom header to a message with the right client or server tools.
+
+## Security
+
+- Try first with the --dummy run to see how many messages will be deleted, because there won't be any prompts and messages get deleted (almost) inmediately.
+- Don't pass the password in the command line, use the --config file to store parameters and protect it with the right permissions.
+- Use SSL or your messages and credentials will be visible in your network (and any networks you need to go throw to get to your mail server).
diff --git a/pyproject.toml b/pyproject.toml
index 30ff2de..b91c991 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -7,7 +7,7 @@ Homepage = "https://susurrando.com"
 
 [project]
 name = "remove_duplicate_imap_messages"
-version = "0.0.2"
+version = "1.0.0"
 description = "Given an IMAP folder look for duplicate messages and optionally delete them"
 readme = "README.md"
 authors = [{ name = "Antonio J. Delgado", email = "ad@susurrando.com" }]
diff --git a/setup.cfg b/setup.cfg
index 533dbf2..0520793 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,6 +1,6 @@
 [metadata]
 name = remove_duplicate_imap_messages
-version = 0.0.2
+version = 1.0.0
 
 [options]
 packages = remove_duplicate_imap_messages