diff --git a/tor-netdoc/src/keyword.rs b/tor-netdoc/src/keyword.rs
index 00418446a..db2ec3ef8 100644
--- a/tor-netdoc/src/keyword.rs
+++ b/tor-netdoc/src/keyword.rs
@@ -25,11 +25,13 @@ pub trait Keyword: Hash + Eq + PartialEq + Copy + Clone {
     fn from_idx(i: usize) -> Option<Self>;
     /// Find a string corresponding to this keyword.  This may not be the
     /// actual string from the document; it is indended for reporting errors.
-    fn to_str(&self) -> &'static str;
+    fn to_str(self) -> &'static str;
     /// Return the index for this keyword.
     fn idx(self) -> usize;
     /// Return the number of indices for this keyword.
     fn n_vals() -> usize;
+    /// Return true iff this keyword denotes an annotation.
+    fn is_annotation(self) -> bool;
     /// Convert from an index to a human-readable string.
     fn idx_to_str(i: usize) -> &'static str {
         Self::from_idx(i)
@@ -37,7 +39,7 @@ pub trait Keyword: Hash + Eq + PartialEq + Copy + Clone {
             .unwrap_or("<out of range>")
     }
     /// Return a new TokenFmtBuilder for creating rules about this keyword.
-    fn rule(&self) -> rules::TokenFmtBuilder<Self> {
-        rules::TokenFmtBuilder::new(*self)
+    fn rule(self) -> rules::TokenFmtBuilder<Self> {
+        rules::TokenFmtBuilder::new(self)
     }
 }
diff --git a/tor-netdoc/src/macros.rs b/tor-netdoc/src/macros.rs
index c5caf1883..f0a694af5 100644
--- a/tor-netdoc/src/macros.rs
+++ b/tor-netdoc/src/macros.rs
@@ -21,7 +21,7 @@
 /// ```
 macro_rules! decl_keyword {
     { $(#[$meta:meta])* $v:vis
-      $name:ident { $( $($s:literal)|+ => $i:ident),* $(,)? } } => {
+      $name:ident { $( $($anno:ident)? $($s:literal)|+ => $i:ident),* $(,)? } } => {
         #[derive(Copy,Clone,Eq,PartialEq,Debug,std::hash::Hash)]
         #[allow(non_camel_case_types)]
         $(#[$meta])*
@@ -61,7 +61,7 @@ macro_rules! decl_keyword {
                 };
                 VALS.get(i).copied()
             }
-            fn to_str(&self) -> &'static str {
+            fn to_str(self) -> &'static str {
                 use $name::*;
                 match self {
                     // TODO: this turns "accept" | "reject" into
@@ -72,6 +72,17 @@ macro_rules! decl_keyword {
                     ANN_UNRECOGNIZED => "<unrecognized annotation>"
                 }
             }
+            fn is_annotation(self) -> bool {
+                use $name::*;
+                match self {
+                    $( $i => decl_keyword![@impl is_anno $($anno)? ], )*
+                    UNRECOGNIZED => false,
+                    ANN_UNRECOGNIZED => true,
+                }
+            }
         }
-    }
+    };
+    [ @impl is_anno annotation ] => ( true );
+    [ @impl is_anno $x:ident ] => ( compile_error!("unrecognized keyword; not annotation") );
+    [ @impl is_anno ] => ( false );
 }
diff --git a/tor-netdoc/src/microdesc.rs b/tor-netdoc/src/microdesc.rs
index 7ded712f4..4f7672928 100644
--- a/tor-netdoc/src/microdesc.rs
+++ b/tor-netdoc/src/microdesc.rs
@@ -1,7 +1,7 @@
 //! Parsing implementation for Tor microdescriptors.
 //!
 //! A "microdescriptor" is an incomplete, infrequently-changing
-//! summary of a relay's informatino information that is generated by
+//! summary of a relay's information that is generated by
 //! the directory authorities.
 //!
 //! Microdescriptors are much smaller than router descriptors, and
@@ -41,6 +41,7 @@ pub struct Microdesc {
 decl_keyword! {
     /// Keyword type for recognized objects in microdescriptors.
     MicrodescKW {
+        annotation "last-listed" => A_LAST_LISTED,
         "onion-key" => ONION_KEY,
         "ntor-onion-key" => NTOR_ONION_KEY,
         "family" => FAMILY,
diff --git a/tor-netdoc/src/routerdesc.rs b/tor-netdoc/src/routerdesc.rs
index 6f32e8a6a..afba602d6 100644
--- a/tor-netdoc/src/routerdesc.rs
+++ b/tor-netdoc/src/routerdesc.rs
@@ -113,6 +113,8 @@ decl_keyword! {
     /// RouterKW is an instance of Keyword, used to denote the different
     /// Items that are recognized as appearing in a router descriptor.
     RouterKW {
+        annotation "@source" => A_SOURCE,
+        annotation "@downloaded-at" => A_DOWNLOADED_AT,
         "accept" | "reject" => POLICY,
         "bandwidth" => BANDWIDTH,
         "bridge-distribution-request" => BRIDGE_DISTRIBUTION_REQUEST,