diff --git a/src/compl/arg.rs b/src/compl/arg.rs
index 984b374..adbbde1 100644
--- a/src/compl/arg.rs
+++ b/src/compl/arg.rs
@@ -1,24 +1,26 @@
-//! Module related to completion arguments.
+//! Module related to completion CLI.
 //!
-//! This module provides subcommands and an argument matcher related to completion.
+//! This module provides subcommands and a command matcher related to completion.
 
 use anyhow::Result;
 use clap::{self, App, Arg, ArgMatches, Shell, SubCommand};
 use log::debug;
 
-/// Enumeration of all possible matches.
-pub enum Match<'a> {
+type OptionShell<'a> = Option<&'a str>;
+
+/// Completion commands.
+pub enum Command<'a> {
     /// Generate completion script for the given shell slice.
-    Generate(&'a str),
+    Generate(OptionShell<'a>),
 }
 
-/// Completion arg matcher.
-pub fn matches<'a>(m: &'a ArgMatches) -> Result<Option<Match<'a>>> {
+/// Completion command matcher.
+pub fn matches<'a>(m: &'a ArgMatches) -> Result<Option<Command<'a>>> {
     if let Some(m) = m.subcommand_matches("completion") {
         debug!("completion command matched");
-        let shell = m.value_of("shell").unwrap();
-        debug!("shell: {}", shell);
-        return Ok(Some(Match::Generate(shell)));
+        let shell = m.value_of("shell");
+        debug!("shell: `{:?}`", shell);
+        return Ok(Some(Command::Generate(shell)));
     };
 
     Ok(None)
diff --git a/src/compl/handler.rs b/src/compl/handler.rs
index 5fb0efc..5c4ca01 100644
--- a/src/compl/handler.rs
+++ b/src/compl/handler.rs
@@ -7,8 +7,8 @@ use clap::{App, Shell};
 use std::{io, str::FromStr};
 
 /// Generate completion script from the given [`clap::App`] for the given shell slice.
-pub fn generate<'a>(shell: &'a str, mut app: App<'a, 'a>) -> Result<()> {
-    let shell = Shell::from_str(shell)
+pub fn generate<'a>(shell: Option<&'a str>, mut app: App<'a, 'a>) -> Result<()> {
+    let shell = Shell::from_str(shell.unwrap_or_default())
         .map_err(|err| anyhow!(err))
         .context("cannot parse shell")?;
     app.gen_completions_to("himalaya", shell, &mut io::stdout());
diff --git a/src/config/arg.rs b/src/config/arg.rs
index 538ecd0..b0f34d8 100644
--- a/src/config/arg.rs
+++ b/src/config/arg.rs
@@ -1,3 +1,7 @@
+//! Module related to config CLI.
+//!
+//! This module provides arguments related to config.
+
 use clap::Arg;
 
 /// Config arguments.
diff --git a/src/domain/imap/arg.rs b/src/domain/imap/arg.rs
index 3c47c32..257f1d4 100644
--- a/src/domain/imap/arg.rs
+++ b/src/domain/imap/arg.rs
@@ -1,34 +1,36 @@
-//! Module related to IMAP arguments.
+//! Module related to IMAP CLI.
 //!
-//! This module provides subcommands and an argument matcher related to IMAP.
+//! This module provides subcommands and a command matcher related to IMAP.
 
 use anyhow::Result;
 use clap::{App, ArgMatches};
 use log::debug;
 
-/// Enumeration of all possible matches.
-pub enum Match {
+type Keepalive = u64;
+
+/// IMAP commands.
+pub enum Command {
     /// Start the IMAP notify mode with the give keepalive duration.
-    Notify(u64),
+    Notify(Keepalive),
 
     /// Start the IMAP watch mode with the give keepalive duration.
-    Watch(u64),
+    Watch(Keepalive),
 }
 
-/// IMAP arg matcher.
-pub fn matches(m: &ArgMatches) -> Result<Option<Match>> {
+/// IMAP command matcher.
+pub fn matches(m: &ArgMatches) -> Result<Option<Command>> {
     if let Some(m) = m.subcommand_matches("notify") {
         debug!("notify command matched");
         let keepalive = clap::value_t_or_exit!(m.value_of("keepalive"), u64);
         debug!("keepalive: {}", keepalive);
-        return Ok(Some(Match::Notify(keepalive)));
+        return Ok(Some(Command::Notify(keepalive)));
     }
 
     if let Some(m) = m.subcommand_matches("watch") {
         debug!("watch command matched");
         let keepalive = clap::value_t_or_exit!(m.value_of("keepalive"), u64);
         debug!("keepalive: {}", keepalive);
-        return Ok(Some(Match::Watch(keepalive)));
+        return Ok(Some(Command::Watch(keepalive)));
     }
 
     Ok(None)
diff --git a/src/domain/mbox/arg.rs b/src/domain/mbox/arg.rs
index d615f49..05d27d6 100644
--- a/src/domain/mbox/arg.rs
+++ b/src/domain/mbox/arg.rs
@@ -1,35 +1,35 @@
-//! Module related to mailboxes arguments.
+//! Module related to mailbox CLI.
 //!
-//! This module provides subcommands and an argument matcher related to mailboxes.
+//! This module provides subcommands, arguments and a command matcher related to mailbox.
 
 use anyhow::Result;
 use clap::{App, Arg, ArgMatches, SubCommand};
 use log::debug;
 
-/// Enumeration of all possible matches.
-pub enum Match {
+/// Mailbox commands.
+pub enum Commands {
     /// List all available mailboxes.
     List,
 }
 
-/// Mailboxes arg matcher.
-pub fn matches(m: &ArgMatches) -> Result<Option<Match>> {
+/// Mailbox command matcher.
+pub fn matches(m: &ArgMatches) -> Result<Option<Commands>> {
     if let Some(_) = m.subcommand_matches("mailboxes") {
         debug!("mailboxes command matched");
-        return Ok(Some(Match::List));
+        return Ok(Some(Commands::List));
     }
 
     Ok(None)
 }
 
-/// Mailboxes subcommands.
+/// Mailbox subcommands.
 pub fn subcmds<'a>() -> Vec<App<'a, 'a>> {
     vec![SubCommand::with_name("mailboxes")
         .aliases(&["mailbox", "mboxes", "mbox", "m"])
         .about("Lists all mailboxes")]
 }
 
-/// Source mailbox arg.
+/// Source mailbox argument.
 pub fn source_arg<'a>() -> Arg<'a, 'a> {
     Arg::with_name("mailbox")
         .short("m")
@@ -39,7 +39,7 @@ pub fn source_arg<'a>() -> Arg<'a, 'a> {
         .default_value("INBOX")
 }
 
-/// Target mailbox arg.
+/// Target mailbox argument.
 pub fn target_arg<'a>() -> Arg<'a, 'a> {
     Arg::with_name("target")
         .help("Specifies the targetted mailbox")
diff --git a/src/domain/msg/arg.rs b/src/domain/msg/arg.rs
index f06fee2..7c0f170 100644
--- a/src/domain/msg/arg.rs
+++ b/src/domain/msg/arg.rs
@@ -1,3 +1,7 @@
+//! Module related to message CLI.
+//!
+//! This module provides subcommands, arguments and a command matcher related to message.
+
 use anyhow::Result;
 use clap::{self, App, Arg, ArgMatches, SubCommand};
 use log::debug;
@@ -15,8 +19,8 @@ type RawMsg<'a> = &'a str;
 type Query = String;
 type AttachmentsPaths<'a> = Vec<&'a str>;
 
-/// Enumeration of all possible matches.
-pub enum Match<'a> {
+/// Message commands.
+pub enum Command<'a> {
     Attachments(Uid<'a>),
     Copy(Uid<'a>, TargetMbox<'a>),
     Delete(Uid<'a>),
@@ -30,16 +34,17 @@ pub enum Match<'a> {
     Send(RawMsg<'a>),
     Write(AttachmentsPaths<'a>),
 
-    Flag(msg::flag::arg::Match<'a>),
-    Tpl(msg::tpl::arg::Match<'a>),
+    Flag(msg::flag::arg::Command<'a>),
+    Tpl(msg::tpl::arg::Command<'a>),
 }
 
-pub fn matches<'a>(m: &'a ArgMatches) -> Result<Option<Match<'a>>> {
+/// Message command matcher.
+pub fn matches<'a>(m: &'a ArgMatches) -> Result<Option<Command<'a>>> {
     if let Some(m) = m.subcommand_matches("attachments") {
         debug!("attachments command matched");
         let uid = m.value_of("uid").unwrap();
         debug!("uid: {}", &uid);
-        return Ok(Some(Match::Attachments(uid)));
+        return Ok(Some(Command::Attachments(uid)));
     }
 
     if let Some(m) = m.subcommand_matches("copy") {
@@ -48,18 +53,18 @@ pub fn matches<'a>(m: &'a ArgMatches) -> Result<Option<Match<'a>>> {
         debug!("uid: {}", &uid);
         let target = m.value_of("target");
         debug!("target mailbox: `{:?}`", target);
-        return Ok(Some(Match::Copy(uid, target)));
+        return Ok(Some(Command::Copy(uid, target)));
     }
 
     if let Some(m) = m.subcommand_matches("delete") {
         debug!("copy command matched");
         let uid = m.value_of("uid").unwrap();
         debug!("uid: {}", &uid);
-        return Ok(Some(Match::Delete(uid)));
+        return Ok(Some(Command::Delete(uid)));
     }
 
     if let Some(m) = msg::flag::arg::matches(&m)? {
-        return Ok(Some(Match::Flag(m)));
+        return Ok(Some(Command::Flag(m)));
     }
 
     if let Some(m) = m.subcommand_matches("forward") {
@@ -68,7 +73,7 @@ pub fn matches<'a>(m: &'a ArgMatches) -> Result<Option<Match<'a>>> {
         let paths: Vec<&str> = m.values_of("attachments").unwrap_or_default().collect();
         debug!("attachments paths: {:?}", paths);
         debug!("uid: {}", &uid);
-        return Ok(Some(Match::Forward(uid, paths)));
+        return Ok(Some(Command::Forward(uid, paths)));
     }
 
     if let Some(m) = m.subcommand_matches("list") {
@@ -83,7 +88,7 @@ pub fn matches<'a>(m: &'a ArgMatches) -> Result<Option<Match<'a>>> {
             .map(|page| 1.max(page) - 1)
             .unwrap_or_default();
         debug!("page: `{:?}`", page);
-        return Ok(Some(Match::List(page_size, page)));
+        return Ok(Some(Command::List(page_size, page)));
     }
 
     if let Some(m) = m.subcommand_matches("move") {
@@ -92,7 +97,7 @@ pub fn matches<'a>(m: &'a ArgMatches) -> Result<Option<Match<'a>>> {
         debug!("uid: {}", &uid);
         let target = m.value_of("target");
         debug!("target mailbox: `{:?}`", target);
-        return Ok(Some(Match::Move(uid, target)));
+        return Ok(Some(Command::Move(uid, target)));
     }
 
     if let Some(m) = m.subcommand_matches("read") {
@@ -102,7 +107,7 @@ pub fn matches<'a>(m: &'a ArgMatches) -> Result<Option<Match<'a>>> {
         debug!("mime: {}", mime);
         let raw = m.is_present("raw");
         debug!("raw: {}", raw);
-        return Ok(Some(Match::Read(uid, mime, raw)));
+        return Ok(Some(Command::Read(uid, mime, raw)));
     }
 
     if let Some(m) = m.subcommand_matches("reply") {
@@ -113,7 +118,7 @@ pub fn matches<'a>(m: &'a ArgMatches) -> Result<Option<Match<'a>>> {
         debug!("reply all: {}", all);
         let paths: Vec<&str> = m.values_of("attachments").unwrap_or_default().collect();
         debug!("attachments paths: {:?}", paths);
-        return Ok(Some(Match::Reply(uid, all, paths)));
+        return Ok(Some(Command::Reply(uid, all, paths)));
     }
 
     if let Some(m) = m.subcommand_matches("save") {
@@ -122,7 +127,7 @@ pub fn matches<'a>(m: &'a ArgMatches) -> Result<Option<Match<'a>>> {
         debug!("message: {}", &msg);
         let target = m.value_of("target");
         debug!("target mailbox: `{:?}`", target);
-        return Ok(Some(Match::Save(target, msg)));
+        return Ok(Some(Command::Save(target, msg)));
     }
 
     if let Some(m) = m.subcommand_matches("search") {
@@ -161,34 +166,32 @@ pub fn matches<'a>(m: &'a ArgMatches) -> Result<Option<Match<'a>>> {
             })
             .1
             .join(" ");
-        return Ok(Some(Match::Search(query, page_size, page)));
+        return Ok(Some(Command::Search(query, page_size, page)));
     }
 
     if let Some(m) = m.subcommand_matches("send") {
         debug!("send command matched");
         let msg = m.value_of("message").unwrap_or_default();
         debug!("message: {}", msg);
-        return Ok(Some(Match::Send(msg)));
+        return Ok(Some(Command::Send(msg)));
     }
 
     if let Some(m) = msg::tpl::arg::matches(&m)? {
-        return Ok(Some(Match::Tpl(m)));
+        return Ok(Some(Command::Tpl(m)));
     }
 
     if let Some(m) = m.subcommand_matches("write") {
         debug!("write command matched");
         let attachment_paths: Vec<&str> = m.values_of("attachments").unwrap_or_default().collect();
         debug!("attachments paths: {:?}", attachment_paths);
-        return Ok(Some(Match::Write(attachment_paths)));
+        return Ok(Some(Command::Write(attachment_paths)));
     }
 
     debug!("default list command matched");
-    Ok(Some(Match::List(None, 0)))
+    Ok(Some(Command::List(None, 0)))
 }
 
-// == Argument Functions ==
-/// Returns an Clap-Argument to be able to use `<UID>` in the commandline like
-/// for the `himalaya read` subcommand.
+/// Message UID argument.
 pub(crate) fn uid_arg<'a>() -> Arg<'a, 'a> {
     Arg::with_name("uid")
         .help("Specifies the targetted message")
@@ -196,6 +199,7 @@ pub(crate) fn uid_arg<'a>() -> Arg<'a, 'a> {
         .required(true)
 }
 
+/// Message reply all argument.
 pub(crate) fn reply_all_arg<'a>() -> Arg<'a, 'a> {
     Arg::with_name("reply-all")
         .help("Includes all recipients")
@@ -203,6 +207,7 @@ pub(crate) fn reply_all_arg<'a>() -> Arg<'a, 'a> {
         .long("all")
 }
 
+/// Message page size argument.
 fn page_size_arg<'a>() -> Arg<'a, 'a> {
     Arg::with_name("page-size")
         .help("Page size")
@@ -211,6 +216,7 @@ fn page_size_arg<'a>() -> Arg<'a, 'a> {
         .value_name("INT")
 }
 
+/// Message page argument.
 fn page_arg<'a>() -> Arg<'a, 'a> {
     Arg::with_name("page")
         .help("Page number")
@@ -220,6 +226,7 @@ fn page_arg<'a>() -> Arg<'a, 'a> {
         .default_value("0")
 }
 
+/// Message attachment argument.
 /// TODO: move to attachment folder
 fn attachment_arg<'a>() -> Arg<'a, 'a> {
     Arg::with_name("attachments")
@@ -230,7 +237,7 @@ fn attachment_arg<'a>() -> Arg<'a, 'a> {
         .multiple(true)
 }
 
-/// Messages subcommands.
+/// Message subcommands.
 pub fn subcmds<'a>() -> Vec<App<'a, 'a>> {
     vec![
         msg::flag::arg::subcmds(),
diff --git a/src/domain/msg/flag/arg.rs b/src/domain/msg/flag/arg.rs
index 4f9fc56..d21b29f 100644
--- a/src/domain/msg/flag/arg.rs
+++ b/src/domain/msg/flag/arg.rs
@@ -1,3 +1,7 @@
+//! Module related to message flag CLI.
+//!
+//! This module provides subcommands, arguments and a command matcher related to message flag.
+
 use anyhow::Result;
 use clap::{self, App, Arg, ArgMatches, SubCommand};
 use log::debug;
@@ -7,22 +11,22 @@ use crate::domain::msg;
 type Uid<'a> = &'a str;
 type Flags<'a> = &'a str;
 
-/// Enumeration of all possible matches.
-pub enum Match<'a> {
+/// Message flag commands.
+pub enum Command<'a> {
     Set(Uid<'a>, Flags<'a>),
     Add(Uid<'a>, Flags<'a>),
     Remove(Uid<'a>, Flags<'a>),
 }
 
-/// Message flag arg matcher.
-pub fn matches<'a>(m: &'a ArgMatches) -> Result<Option<Match<'a>>> {
+/// Message flag command matcher.
+pub fn matches<'a>(m: &'a ArgMatches) -> Result<Option<Command<'a>>> {
     if let Some(m) = m.subcommand_matches("set") {
         debug!("set command matched");
         let uid = m.value_of("uid").unwrap();
         debug!("uid: {}", uid);
         let flags = m.value_of("flags").unwrap();
         debug!("flags: {}", flags);
-        return Ok(Some(Match::Set(uid, flags)));
+        return Ok(Some(Command::Set(uid, flags)));
     }
 
     if let Some(m) = m.subcommand_matches("add") {
@@ -31,7 +35,7 @@ pub fn matches<'a>(m: &'a ArgMatches) -> Result<Option<Match<'a>>> {
         debug!("uid: {}", uid);
         let flags = m.value_of("flags").unwrap();
         debug!("flags: {}", flags);
-        return Ok(Some(Match::Add(uid, flags)));
+        return Ok(Some(Command::Add(uid, flags)));
     }
 
     if let Some(m) = m.subcommand_matches("remove") {
@@ -40,13 +44,13 @@ pub fn matches<'a>(m: &'a ArgMatches) -> Result<Option<Match<'a>>> {
         debug!("uid: {}", uid);
         let flags = m.value_of("flags").unwrap();
         debug!("flags: {}", flags);
-        return Ok(Some(Match::Remove(uid, flags)));
+        return Ok(Some(Command::Remove(uid, flags)));
     }
 
     Ok(None)
 }
 
-/// Message flag arg.
+/// Message flag flags argument.
 fn flags_arg<'a>() -> Arg<'a, 'a> {
     Arg::with_name("flags")
         .help("IMAP flags (see https://tools.ietf.org/html/rfc3501#page-11). Just write the flag name without the backslash. Example: --flags \"Seen Answered\"")
diff --git a/src/domain/msg/tpl/arg.rs b/src/domain/msg/tpl/arg.rs
index efcc25b..bee9e38 100644
--- a/src/domain/msg/tpl/arg.rs
+++ b/src/domain/msg/tpl/arg.rs
@@ -1,3 +1,7 @@
+//! Module related to message template CLI.
+//!
+//! This module provides subcommands, arguments and a command matcher related to message template.
+
 use anyhow::Result;
 use clap::{self, App, Arg, ArgMatches, SubCommand};
 use log::debug;
@@ -7,18 +11,18 @@ use crate::domain::msg::{self, arg::uid_arg};
 type Uid<'a> = &'a str;
 type All = bool;
 
-/// Enumeration of all possible matches.
-pub enum Match<'a> {
+/// Message template commands.
+pub enum Command<'a> {
     New,
     Reply(Uid<'a>, All),
     Forward(Uid<'a>),
 }
 
-/// Message template arg matcher.
-pub fn matches<'a>(m: &'a ArgMatches) -> Result<Option<Match<'a>>> {
+/// Message template command matcher.
+pub fn matches<'a>(m: &'a ArgMatches) -> Result<Option<Command<'a>>> {
     if let Some(_) = m.subcommand_matches("new") {
         debug!("new command matched");
-        return Ok(Some(Match::New));
+        return Ok(Some(Command::New));
     }
 
     if let Some(m) = m.subcommand_matches("reply") {
@@ -27,14 +31,14 @@ pub fn matches<'a>(m: &'a ArgMatches) -> Result<Option<Match<'a>>> {
         debug!("uid: {}", uid);
         let all = m.is_present("reply-all");
         debug!("reply all: {}", all);
-        return Ok(Some(Match::Reply(uid, all)));
+        return Ok(Some(Command::Reply(uid, all)));
     }
 
     if let Some(m) = m.subcommand_matches("forward") {
         debug!("forward command matched");
         let uid = m.value_of("uid").unwrap();
         debug!("uid: {}", uid);
-        return Ok(Some(Match::Forward(uid)));
+        return Ok(Some(Command::Forward(uid)));
     }
 
     Ok(None)
diff --git a/src/main.rs b/src/main.rs
index a735786..e9b964d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -58,7 +58,7 @@ fn main() -> Result<()> {
     // Check completion match BEFORE any entity or service initialization.
     // See https://github.com/soywod/himalaya/issues/115.
     match compl::arg::matches(&m)? {
-        Some(compl::arg::Match::Generate(shell)) => {
+        Some(compl::arg::Command::Generate(shell)) => {
             return compl::handler::generate(shell, create_app());
         }
         _ => (),
@@ -73,10 +73,10 @@ fn main() -> Result<()> {
 
     // Check IMAP matches.
     match imap::arg::matches(&m)? {
-        Some(imap::arg::Match::Notify(keepalive)) => {
+        Some(imap::arg::Command::Notify(keepalive)) => {
             return imap::handler::notify(keepalive, &config, &mut imap);
         }
-        Some(imap::arg::Match::Watch(keepalive)) => {
+        Some(imap::arg::Command::Watch(keepalive)) => {
             return imap::handler::watch(keepalive, &mut imap);
         }
         _ => (),
@@ -84,7 +84,7 @@ fn main() -> Result<()> {
 
     // Check mailbox matches.
     match mbox::arg::matches(&m)? {
-        Some(mbox::arg::Match::List) => {
+        Some(mbox::arg::Commands::List) => {
             return mbox::handler::list(&output, &mut imap);
         }
         _ => (),
@@ -92,62 +92,62 @@ fn main() -> Result<()> {
 
     // Check message matches.
     match msg::arg::matches(&m)? {
-        Some(msg::arg::Match::Attachments(uid)) => {
+        Some(msg::arg::Command::Attachments(uid)) => {
             return msg::handler::attachments(uid, &account, &output, &mut imap);
         }
-        Some(msg::arg::Match::Copy(uid, mbox)) => {
+        Some(msg::arg::Command::Copy(uid, mbox)) => {
             return msg::handler::copy(uid, mbox, &output, &mut imap);
         }
-        Some(msg::arg::Match::Delete(uid)) => {
+        Some(msg::arg::Command::Delete(uid)) => {
             return msg::handler::delete(uid, &output, &mut imap);
         }
-        Some(msg::arg::Match::Forward(uid, paths)) => {
+        Some(msg::arg::Command::Forward(uid, paths)) => {
             return msg::handler::forward(uid, paths, &account, &output, &mut imap, &mut smtp);
         }
-        Some(msg::arg::Match::List(page_size, page)) => {
+        Some(msg::arg::Command::List(page_size, page)) => {
             return msg::handler::list(page_size, page, &account, &output, &mut imap);
         }
-        Some(msg::arg::Match::Move(uid, mbox)) => {
+        Some(msg::arg::Command::Move(uid, mbox)) => {
             return msg::handler::move_(uid, mbox, &output, &mut imap);
         }
-        Some(msg::arg::Match::Read(uid, mime, raw)) => {
+        Some(msg::arg::Command::Read(uid, mime, raw)) => {
             return msg::handler::read(uid, mime, raw, &output, &mut imap);
         }
-        Some(msg::arg::Match::Reply(uid, all, paths)) => {
+        Some(msg::arg::Command::Reply(uid, all, paths)) => {
             return msg::handler::reply(uid, all, paths, &account, &output, &mut imap, &mut smtp);
         }
-        Some(msg::arg::Match::Save(mbox, msg)) => {
+        Some(msg::arg::Command::Save(mbox, msg)) => {
             return msg::handler::save(mbox, msg, &mut imap);
         }
-        Some(msg::arg::Match::Search(query, page_size, page)) => {
+        Some(msg::arg::Command::Search(query, page_size, page)) => {
             return msg::handler::search(page_size, page, query, &account, &output, &mut imap);
         }
-        Some(msg::arg::Match::Send(msg)) => {
+        Some(msg::arg::Command::Send(msg)) => {
             return msg::handler::send(msg, &output, &mut imap, &mut smtp);
         }
-        Some(msg::arg::Match::Write(paths)) => {
+        Some(msg::arg::Command::Write(paths)) => {
             return msg::handler::write(paths, &account, &output, &mut imap, &mut smtp);
         }
 
-        Some(msg::arg::Match::Flag(m)) => match m {
-            msg::flag::arg::Match::Set(uid, flags) => {
+        Some(msg::arg::Command::Flag(m)) => match m {
+            msg::flag::arg::Command::Set(uid, flags) => {
                 return msg::flag::handler::set(uid, flags, &mut imap);
             }
-            msg::flag::arg::Match::Add(uid, flags) => {
+            msg::flag::arg::Command::Add(uid, flags) => {
                 return msg::flag::handler::add(uid, flags, &mut imap);
             }
-            msg::flag::arg::Match::Remove(uid, flags) => {
+            msg::flag::arg::Command::Remove(uid, flags) => {
                 return msg::flag::handler::remove(uid, flags, &mut imap);
             }
         },
-        Some(msg::arg::Match::Tpl(m)) => match m {
-            msg::tpl::arg::Match::New => {
+        Some(msg::arg::Command::Tpl(m)) => match m {
+            msg::tpl::arg::Command::New => {
                 return msg::tpl::handler::new(&account, &output, &mut imap);
             }
-            msg::tpl::arg::Match::Reply(uid, all) => {
+            msg::tpl::arg::Command::Reply(uid, all) => {
                 return msg::tpl::handler::reply(uid, all, &account, &output, &mut imap);
             }
-            msg::tpl::arg::Match::Forward(uid) => {
+            msg::tpl::arg::Command::Forward(uid) => {
                 return msg::tpl::handler::forward(uid, &account, &output, &mut imap);
             }
         },
diff --git a/src/output/arg.rs b/src/output/arg.rs
index b4c49ad..84417b8 100644
--- a/src/output/arg.rs
+++ b/src/output/arg.rs
@@ -1,3 +1,7 @@
+//! Module related to output CLI.
+//!
+//! This module provides arguments related to output.
+
 use clap::Arg;
 
 /// Output arguments.