diff --git a/src/command_line.rs b/src/command_line.rs
index e6db4b82..24d04038 100644
--- a/src/command_line.rs
+++ b/src/command_line.rs
@@ -12,40 +12,39 @@ use serde::Serialize;
 #[derive(Debug, Default, Parser)]
 #[command(rename_all = "kebab-case")]
 pub struct SliceOptions {
-    /// List of slice files to compile.
+    /// List of Slice files to compile.
     #[arg(required = true)]
     pub sources: Vec<String>,
 
-    /// Files that are needed for referencing, but that no code should be generated for.
-    #[arg(short = 'R', long, num_args = 1, action = Append)]
+    /// Add a directory or Slice file to the list of references.
+    #[arg(short = 'R', value_name="REFERENCE", num_args = 1, action = Append)]
     pub references: Vec<String>,
 
-    /// Preprocessor Symbols defined on the command line.
-    #[arg(short = 'D', long, num_args = 1, action = Append)]
+    /// Define a preprocessor definition.
+    #[arg(short = 'D', value_name="DEFINITION", num_args = 1, action = Append)]
     pub definitions: Vec<String>,
 
-    /// Instructs the compiler to treat warnings as errors.
-    #[arg(short, long)]
+    /// Instruct the compiler to treat warnings as errors.
+    #[arg(short = 'W')]
     pub warn_as_error: bool,
 
-    /// Instructs the compiler to allow warnings. Specify a list of warnings to allow, or leave empty to allow all
-    /// warnings.
-    #[arg(long)]
-    pub allow_warnings: Option<Vec<String>>,
+    /// Instruct the compiler to allow (not emit) the specified warning.
+    #[arg(short = 'A', long = "allow", value_name="WARNING", num_args = 1, action = Append)]
+    pub allowed_warnings: Option<Vec<String>>,
 
-    /// Validates input files without generating code for them.
+    /// Validate input files without generating code for them.
     #[arg(long)]
     pub dry_run: bool,
 
-    /// Output directory for generated code, defaults to the current working directory.
-    #[arg(long)]
+    /// Set the output directory for the generated code. Defaults to the current working directory.
+    #[arg(short = 'O', long)]
     pub output_dir: Option<String>,
 
-    /// Output format for emitted errors.
+    /// Set the output format for emitted errors.
     #[arg(value_enum, default_value_t = DiagnosticFormat::Human, long, ignore_case = true)]
     pub diagnostic_format: DiagnosticFormat,
 
-    /// Disables ANSI escape code for diagnostic output.
+    /// Disable ANSI color codes in diagnostic output.
     #[arg(long)]
     pub disable_color: bool,
 }
diff --git a/src/diagnostics/diagnostic_reporter.rs b/src/diagnostics/diagnostic_reporter.rs
index 4a36b535..429db79e 100644
--- a/src/diagnostics/diagnostic_reporter.rs
+++ b/src/diagnostics/diagnostic_reporter.rs
@@ -39,7 +39,7 @@ impl DiagnosticReporter {
             treat_warnings_as_errors: slice_options.warn_as_error,
             diagnostic_format: slice_options.diagnostic_format,
             disable_color: slice_options.disable_color,
-            allowed_warnings: slice_options.allow_warnings.clone(),
+            allowed_warnings: slice_options.allowed_warnings.clone(),
         }
     }
 
diff --git a/tests/diagnostic_output_tests.rs b/tests/diagnostic_output_tests.rs
index 690dcba9..a136c415 100644
--- a/tests/diagnostic_output_tests.rs
+++ b/tests/diagnostic_output_tests.rs
@@ -120,7 +120,7 @@ error [E010]: invalid enum 'E': enums must contain at least one enumerator
         // Set the output format to JSON.
         let options = SliceOptions {
             diagnostic_format: DiagnosticFormat::Json,
-            allow_warnings: Some(vec![]),
+            allowed_warnings: Some(vec![]),
             ..Default::default()
         };
 
@@ -151,7 +151,7 @@ error [E010]: invalid enum 'E': enums must contain at least one enumerator
         // Set the output format to JSON.
         let options = SliceOptions {
             diagnostic_format: DiagnosticFormat::Json,
-            allow_warnings: Some(vec!["W004".to_string()]),
+            allowed_warnings: Some(vec!["W004".to_string()]),
             ..Default::default()
         };