diff --git a/amazonka-route53-domains.cabal b/amazonka-route53-domains.cabal
--- a/amazonka-route53-domains.cabal
+++ b/amazonka-route53-domains.cabal
@@ -1,5 +1,5 @@
 name:                  amazonka-route53-domains
-version:               0.3.4
+version:               0.3.5
 synopsis:              Amazon Route 53 Domains SDK.
 homepage:              https://github.com/brendanhay/amazonka
 license:               OtherLicense
@@ -56,5 +56,5 @@
     other-modules:
 
     build-depends:
-          amazonka-core == 0.3.4.*
+          amazonka-core == 0.3.5.*
         , base          >= 4.7     && < 5
diff --git a/gen/Network/AWS/Route53Domains/CheckDomainAvailability.hs b/gen/Network/AWS/Route53Domains/CheckDomainAvailability.hs
--- a/gen/Network/AWS/Route53Domains/CheckDomainAvailability.hs
+++ b/gen/Network/AWS/Route53Domains/CheckDomainAvailability.hs
@@ -118,7 +118,10 @@
 -- name is reserved under specific conditions.  'AVAILABLE_PREORDER' – The domain
 -- name is available and can be preordered.  'UNAVAILABLE' – The domain name is
 -- not available.  'UNAVAILABLE_PREMIUM' – The domain name is not available.  'UNAVAILABLE_RESTRICTED' – The domain name is forbidden.  'RESERVED' – The domain name has been
--- reserved for another person or organization.
+-- reserved for another person or organization.  'DONT_KNOW' – The TLD registry
+-- didn't reply with a definitive answer about whether the domain name is
+-- available. Amazon Route 53 can return this response for a variety of reasons,
+-- for example, the registry is performing maintenance. Try again later.
 cdarAvailability :: Lens' CheckDomainAvailabilityResponse DomainAvailability
 cdarAvailability = lens _cdarAvailability (\s a -> s { _cdarAvailability = a })
 
diff --git a/gen/Network/AWS/Route53Domains/Types.hs b/gen/Network/AWS/Route53Domains/Types.hs
--- a/gen/Network/AWS/Route53Domains/Types.hs
+++ b/gen/Network/AWS/Route53Domains/Types.hs
@@ -243,7 +243,7 @@
 --
 -- Default: None
 --
--- Valid values: A-Z, a-z, 0-9, space, ".:/=+\-%@"
+-- Valid values: A-Z, a-z, 0-9, space, ".:/=+\-@"
 --
 -- Constraints: Each key can be 1-128 characters long.
 --
@@ -257,7 +257,7 @@
 --
 -- Default: None
 --
--- Valid values: A-Z, a-z, 0-9, space, ".:/=+\-%@"
+-- Valid values: A-Z, a-z, 0-9, space, ".:/=+\-@"
 --
 -- Constraints: Each value can be 0-256 characters long.
 --
@@ -455,6 +455,7 @@
     = Available             -- ^ AVAILABLE
     | AvailablePreorder     -- ^ AVAILABLE_PREORDER
     | AvailableReserved     -- ^ AVAILABLE_RESERVED
+    | DontKnow              -- ^ DONT_KNOW
     | Reserved              -- ^ RESERVED
     | Unavailable           -- ^ UNAVAILABLE
     | UnavailablePremium    -- ^ UNAVAILABLE_PREMIUM
@@ -468,6 +469,7 @@
         "available"              -> pure Available
         "available_preorder"     -> pure AvailablePreorder
         "available_reserved"     -> pure AvailableReserved
+        "dont_know"              -> pure DontKnow
         "reserved"               -> pure Reserved
         "unavailable"            -> pure Unavailable
         "unavailable_premium"    -> pure UnavailablePremium
@@ -480,6 +482,7 @@
         Available             -> "AVAILABLE"
         AvailablePreorder     -> "AVAILABLE_PREORDER"
         AvailableReserved     -> "AVAILABLE_RESERVED"
+        DontKnow              -> "DONT_KNOW"
         Reserved              -> "RESERVED"
         Unavailable           -> "UNAVAILABLE"
         UnavailablePremium    -> "UNAVAILABLE_PREMIUM"
diff --git a/gen/Network/AWS/Route53Domains/UpdateTagsForDomain.hs b/gen/Network/AWS/Route53Domains/UpdateTagsForDomain.hs
--- a/gen/Network/AWS/Route53Domains/UpdateTagsForDomain.hs
+++ b/gen/Network/AWS/Route53Domains/UpdateTagsForDomain.hs
@@ -108,7 +108,7 @@
 -- Default: None
 --
 -- Valid values: Unicode characters including alphanumeric, space, and
--- ".:/=+\-%@"
+-- ".:/=+\-@"
 --
 -- Constraints: Each key can be 1-128 characters long.
 --
@@ -123,7 +123,7 @@
 -- Default: None
 --
 -- Valid values: Unicode characters including alphanumeric, space, and
--- ".:/=+\-%@"
+-- ".:/=+\-@"
 --
 -- Constraints: Each value can be 0-256 characters long.
 --