diff --git a/.milpa/commands/dev/ci.sh b/.milpa/commands/dev/ci.sh
index 9bfb3e1..73be738 100644
--- a/.milpa/commands/dev/ci.sh
+++ b/.milpa/commands/dev/ci.sh
@@ -2,5 +2,5 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright © 2022 Roberto Hidalgo <chinampa@un.rob.mx>
 
-milpa dev lint || @milpa.fail "linter has errors"
+milpa dev lint || @milpa.fail "linter found errors"
 milpa dev test unit || @milpa.fail "tests failed"
diff --git a/internal/registry/registry.go b/internal/registry/registry.go
index 52c5f62..abcbe45 100644
--- a/internal/registry/registry.go
+++ b/internal/registry/registry.go
@@ -12,7 +12,6 @@ import (
 	"git.rob.mx/nidito/chinampa/pkg/command"
 	"git.rob.mx/nidito/chinampa/pkg/errors"
 	"git.rob.mx/nidito/chinampa/pkg/logger"
-	"git.rob.mx/nidito/chinampa/pkg/statuscode"
 	"github.com/fatih/color"
 	"github.com/spf13/cobra"
 )
@@ -91,9 +90,6 @@ func Execute(version string) error {
 			if idx == len(cmd.Path)-1 {
 				leaf := ToCobra(cmd, cmdRoot.Options)
 				container.AddCommand(leaf)
-				if container != ccRoot {
-					container.ValidArgs = append(container.ValidArgs, leaf.Name())
-				}
 				log.Tracef("cobra: %s => %s", leaf.Name(), container.CommandPath())
 				break
 			}
@@ -151,8 +147,8 @@ func Execute(version string) error {
 							}
 							return errors.NotFound{Msg: "No subcommand provided", Group: []string{}}
 						}
-						os.Exit(statuscode.NotFound)
-						return nil
+
+						return errors.NotFound{Msg: fmt.Sprintf("Unknown subcommand %s", args[0]), Group: []string{}}
 					},
 				}
 
diff --git a/pkg/env/env.go b/pkg/env/env.go
index f9f4e5a..8d1d413 100644
--- a/pkg/env/env.go
+++ b/pkg/env/env.go
@@ -1,12 +1,45 @@
 // Copyright © 2022 Roberto Hidalgo <chinampa@un.rob.mx>
 // SPDX-License-Identifier: Apache-2.0
+
+/*
+Package env holds environment variable names that are meant to be overridden by implementations.
+
+# example
+
+	package main
+
+	import "git.rob.mx/nidito/chinampa/env"
+
+	func init() {
+		env.HelpUnstyled = "MY_APP_PLAIN_HELP"
+		env.HelpStyle = "MY_APP_HELP_STYLE"
+		env.Verbose = "MY_APP_VERBOSE"
+		env.Silent = "MY_APP_SILENT"
+		env.ValidationDisabled = "MY_APP_SKIP_VALIDATION"
+	}
+*/
 package env
 
+// HelpUnstyled means help will not be colored nor formatted for a TTY.
 var HelpUnstyled = "HELP_STYLE_PLAIN"
+
+// HelpStyle identifies the theme to use for help formatting.
 var HelpStyle = "HELP_STYLE"
+
+// Verbose enables verbose printing of log entries.
 var Verbose = "VERBOSE"
+
+// Silent disables all printing of log entries, except for errors.
 var Silent = "SILENT"
+
+// NoColor disables printing of color escape codes in help and log entries.
 var NoColor = "NO_COLOR"
+
+// ForceColor enables printing of color escape codes in help and log entries.
 var ForceColor = "COLOR"
+
+// ValidationDisabled disables validation on arguments and options.
 var ValidationDisabled = "SKIP_VALIDATION"
+
+// Debug enables printing of debugging information.
 var Debug = "DEBUG"
diff --git a/pkg/errors/errors.go b/pkg/errors/errors.go
index f21013b..64c4f28 100644
--- a/pkg/errors/errors.go
+++ b/pkg/errors/errors.go
@@ -2,11 +2,13 @@
 // SPDX-License-Identifier: Apache-2.0
 package errors
 
+// NotFound happens when a sub-command was not found.
 type NotFound struct {
 	Msg   string
 	Group []string
 }
 
+// BadArguments happens when the user provided incorrect arguments or options.
 type BadArguments struct {
 	Msg string
 }
diff --git a/pkg/errors/handler.go b/pkg/errors/handler.go
index cce6b3a..d63a15e 100644
--- a/pkg/errors/handler.go
+++ b/pkg/errors/handler.go
@@ -22,6 +22,7 @@ func showHelp(cmd *cobra.Command) {
 	}
 }
 
+// HandleCobraExit is called when a command errors out or was not found.
 func HandleCobraExit(cmd *cobra.Command, err error) error {
 	if err == nil {
 		ok, err := cmd.PersistentFlags().GetBool(_c.HelpCommandName)
diff --git a/pkg/exec/exec.go b/pkg/exec/exec.go
index 2e9cef2..99e5fdb 100644
--- a/pkg/exec/exec.go
+++ b/pkg/exec/exec.go
@@ -18,6 +18,7 @@ import (
 // ExecFunc is replaced in tests.
 var ExecFunc = WithSubshell
 
+// WithSubshell is the default runner of subprocesses.
 func WithSubshell(ctx context.Context, env []string, executable string, args ...string) (bytes.Buffer, bytes.Buffer, error) {
 	cmd := os_exec.CommandContext(ctx, executable, args...) // #nosec G204
 	var stdout bytes.Buffer
diff --git a/pkg/logger/formatter.go b/pkg/logger/formatter.go
index 42c9ae8..58191e5 100644
--- a/pkg/logger/formatter.go
+++ b/pkg/logger/formatter.go
@@ -33,10 +33,10 @@ func init() {
 	dimmed.EnableColor()
 }
 
-type Formatter struct {
+type ttyFormatter struct {
 }
 
-func (f *Formatter) Format(entry *logrus.Entry) ([]byte, error) {
+func (f *ttyFormatter) Format(entry *logrus.Entry) ([]byte, error) {
 	prefix := ""
 	colorEnabled := runtime.ColorEnabled()
 	message := entry.Message
diff --git a/pkg/logger/log.go b/pkg/logger/log.go
index 59bc071..393e4da 100644
--- a/pkg/logger/log.go
+++ b/pkg/logger/log.go
@@ -12,7 +12,7 @@ import (
 var componentKey = "_component"
 
 func init() {
-	logrus.SetFormatter(new(Formatter))
+	logrus.SetFormatter(new(ttyFormatter))
 }
 
 var Main = logrus.WithContext(context.Background())
@@ -21,18 +21,23 @@ func Sub(name string) *logrus.Entry {
 	return logrus.WithField(componentKey, name)
 }
 
+// Level is a log entry severity level.
 type Level int
 
 const (
-	LevelPanic Level = iota
-	LevelFatal
-	LevelError
+	// LevelError is the most severe.
+	LevelError Level = iota + 2
+	// LevelWarning happens when something is potentially off.
 	LevelWarning
+	// LevelInfo is regular information relayed back to the user.
 	LevelInfo
+	// LevelDebug is debugging information.
 	LevelDebug
+	// LevelTrace is verbose debugging information.
 	LevelTrace
 )
 
+// Configure sets up the Main logger.
 func Configure(name string, level Level) {
 	Main = logrus.WithField(componentKey, name)
 	if runtime.SilenceEnabled() {
diff --git a/pkg/logger/log_test.go b/pkg/logger/log_test.go
index c7378bf..642f77e 100644
--- a/pkg/logger/log_test.go
+++ b/pkg/logger/log_test.go
@@ -29,7 +29,7 @@ func withEnv(t *testing.T, env map[string]string) {
 	}
 
 	t.Cleanup(func() {
-		rt.ResetParsedFlags()
+		rt.ResetParsedFlagsCache()
 
 		for k := range env {
 			os.Unsetenv(k)
diff --git a/pkg/render/render.go b/pkg/render/render.go
index 29d5924..f98639f 100644
--- a/pkg/render/render.go
+++ b/pkg/render/render.go
@@ -20,6 +20,7 @@ func addBackticks(str []byte) []byte {
 	return bytes.ReplaceAll(str, []byte("﹅"), []byte("`"))
 }
 
+// Markdown renders markdown-formatted content to the tty.
 func Markdown(content []byte, withColor bool) ([]byte, error) {
 	content = addBackticks(content)
 
diff --git a/pkg/runtime/runtime.go b/pkg/runtime/runtime.go
index 873bb61..caafc9d 100644
--- a/pkg/runtime/runtime.go
+++ b/pkg/runtime/runtime.go
@@ -1,5 +1,9 @@
 // Copyright © 2022 Roberto Hidalgo <chinampa@un.rob.mx>
 // SPDX-License-Identifier: Apache-2.0
+
+/*
+Package runtime presents environment related information useful during your program's runtime.
+*/
 package runtime
 
 import (
@@ -9,6 +13,8 @@ import (
 	"git.rob.mx/nidito/chinampa/pkg/env"
 )
 
+// Executable is the name of our binary, and should be set
+// using `chinampa.Execute(config chinampa.Config)`.
 var Executable = "chinampa"
 
 var falseIshValues = []string{
@@ -54,7 +60,8 @@ func isTrueIsh(val string) bool {
 
 var _flags map[string]bool
 
-func ResetParsedFlags() {
+// ResetParsedFlagsCache resets the cached parsed global flags.
+func ResetParsedFlagsCache() {
 	_flags = nil
 }
 
@@ -85,14 +92,17 @@ func flagInArgs(name string) bool {
 	return ok
 }
 
+// DebugEnabled tells if debugging was requested.
 func DebugEnabled() bool {
 	return isTrueIsh(os.Getenv(env.Debug))
 }
 
+// DebugEnabled tells if debugging was requested.
 func ValidationEnabled() bool {
 	return !flagInArgs("skip-validation") && isFalseIsh(os.Getenv(env.ValidationDisabled))
 }
 
+// VerboseEnabled tells if verbose output was requested.
 func VerboseEnabled() bool {
 	if flagInArgs("silent") {
 		return false
@@ -100,6 +110,7 @@ func VerboseEnabled() bool {
 	return isTrueIsh(os.Getenv(env.Verbose)) || flagInArgs("verbose")
 }
 
+// SilenceEnabled tells if silencing of output was requested.
 func SilenceEnabled() bool {
 	if flagInArgs("verbose") {
 		return false
@@ -111,6 +122,7 @@ func SilenceEnabled() bool {
 	return isTrueIsh(os.Getenv(env.Silent)) || flagInArgs("silent")
 }
 
+// ColorEnabled tells if colorizing output was requested.
 func ColorEnabled() bool {
 	if flagInArgs("color") {
 		return true
@@ -120,11 +132,12 @@ func ColorEnabled() bool {
 	return !(isTrueIsh(os.Getenv(env.NoColor)) || UnstyledHelpEnabled() || flagInArgs("no-color"))
 }
 
+// UnstyledHelpEnabled tells if help should be printed without formatting.
 func UnstyledHelpEnabled() bool {
 	return isTrueIsh(os.Getenv(env.HelpUnstyled))
 }
 
-// EnvironmentMap returns the resolved environment map.
+// EnvironmentMap returns a map of environment keys for color, debugging and verbosity and their values, ready for `os.Setenv`.
 func EnvironmentMap() map[string]string {
 	res := map[string]string{}
 	trueString := strconv.FormatBool(true)
diff --git a/pkg/runtime/runtime_test.go b/pkg/runtime/runtime_test.go
index f3b60f8..c322de8 100644
--- a/pkg/runtime/runtime_test.go
+++ b/pkg/runtime/runtime_test.go
@@ -27,7 +27,7 @@ func withEnv(t *testing.T, env map[string]string) {
 	}
 
 	t.Cleanup(func() {
-		ResetParsedFlags()
+		ResetParsedFlagsCache()
 
 		for k := range env {
 			os.Unsetenv(k)
diff --git a/pkg/statuscode/statuscode.go b/pkg/statuscode/statuscode.go
index b8504d2..f85011e 100644
--- a/pkg/statuscode/statuscode.go
+++ b/pkg/statuscode/statuscode.go
@@ -1,22 +1,25 @@
 // Copyright © 2022 Roberto Hidalgo <chinampa@un.rob.mx>
 // SPDX-License-Identifier: Apache-2.0
+
+/*
+package statuscode manages exit codes for programs.
+
+See `man sysexits || grep "#define EX" /usr/include/sysexits.h`
+and https://tldp.org/LDP/abs/html/exitcodes.html
+*/
 package statuscode
 
-// Exit statuses
-// see man sysexits || grep "#define EX" /usr/include/sysexits.h
-// and https://tldp.org/LDP/abs/html/exitcodes.html
 const (
-	// 0 means everything is fine.
+	// Ok means everything is fine.
 	Ok = 0
-	// 42 provides answers to life, the universe and everything; also, renders help.
+	// RenderHelp provides answers to life, the universe and everything; also, renders help.
 	RenderHelp = 42
-	// 64 bad arguments
-	// EX_USAGE The command was used incorrectly, e.g., with the wrong number of arguments, a bad flag, a bad syntax in a parameter, or whatever.
+	// Usage means bad arguments were provided by the user.
 	Usage = 64
-	// EX_SOFTWARE An internal software error has been detected. This should be limited to non-operating system related errors as possible.
+	// ProgrammerError means the developer made a mistake.
 	ProgrammerError = 70
-	// EX_CONFIG Something was found in an unconfigured or misconfigured state.
+	// ConfigError means configuration files or the environment is misconfigured.
 	ConfigError = 78
-	// 127 command not found.
+	// NotFound means a sub-command not was found.
 	NotFound = 127
 )