--- a/servo/components/style/properties/properties.mako.rs
+++ b/servo/components/style/properties/properties.mako.rs
@@ -3816,17 +3816,24 @@ impl AliasId {
             AliasedPropertyId::Shorthand(ShorthandId::${alias.original.camel_case}),
             % endif
         % endfor
         ];
         MAP[self as usize]
     }
 }
 
-// NOTE(emilio): Callers are responsible to deal with prefs.
+/// Call the given macro with tokens like this for each longhand and shorthand properties
+/// that is enabled in content:
+///
+/// ```
+/// [CamelCaseName, SetCamelCaseName, PropertyId::Longhand(LonghandId::CamelCaseName)],
+/// ```
+///
+/// NOTE(emilio): Callers are responsible to deal with prefs.
 #[macro_export]
 macro_rules! css_properties_accessors {
     ($macro_name: ident) => {
         $macro_name! {
             % for kind, props in [("Longhand", data.longhands), ("Shorthand", data.shorthands)]:
                 % for property in props:
                     % if property.enabled_in_content():
                         % for prop in [property] + property.alias:
@@ -3839,16 +3846,24 @@ macro_rules! css_properties_accessors {
                         % endfor
                     % endif
                 % endfor
             % endfor
         }
     }
 }
 
+/// Call the given macro with tokens like this for each longhand properties:
+///
+/// ```
+/// { snake_case_ident, true }
+/// ```
+///
+/// … where the boolean indicates whether the property value type
+/// is wrapped in a `Box<_>` in the corresponding `PropertyDeclaration` variant.
 #[macro_export]
 macro_rules! longhand_properties_idents {
     ($macro_name: ident) => {
         $macro_name! {
             % for property in data.longhands:
                 { ${property.ident}, ${"true" if property.boxed else "false"} }
             % endfor
         }

--- a/servo/components/style_traits/values.rs
+++ b/servo/components/style_traits/values.rs
@@ -427,17 +427,17 @@ impl_to_css_for_predefined_type!(i8);
 impl_to_css_for_predefined_type!(i32);
 impl_to_css_for_predefined_type!(u16);
 impl_to_css_for_predefined_type!(u32);
 impl_to_css_for_predefined_type!(::cssparser::Token<'a>);
 impl_to_css_for_predefined_type!(::cssparser::RGBA);
 impl_to_css_for_predefined_type!(::cssparser::Color);
 impl_to_css_for_predefined_type!(::cssparser::UnicodeRange);
 
-#[macro_export]
+/// Define an enum type with unit variants that each corrsepond to a CSS keyword.
 macro_rules! define_css_keyword_enum {
     (pub enum $name:ident { $($variant:ident = $css:expr,)+ }) => {
         #[allow(missing_docs)]
         #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
         #[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq)]
         pub enum $name {
             $($variant),+
         }