diff --git a/examples/dig.rs b/examples/dig.rs
index ae05edd1..cbd46863 100644
--- a/examples/dig.rs
+++ b/examples/dig.rs
@@ -9,10 +9,10 @@ use std::io;
 use std::result;
 use std::str::FromStr;
 use domain::bits::{ComposeError, FromStrError, ParseError};
-use domain::bits::{Class, RRType};
 use domain::bits::message::{MessageBuf, RecordIter};
 use domain::bits::name::{DName, DNameBuf, DNameSlice};
 use domain::bits::rdata::GenericRecordData;
+use domain::iana::{Class, RRType};
 use domain::resolv::{ResolvConf, Resolver, Query};
 
 
diff --git a/src/bits/header.rs b/src/bits/header.rs
index 7439521b..b03b7c1d 100644
--- a/src/bits/header.rs
+++ b/src/bits/header.rs
@@ -13,8 +13,8 @@
 //!
 
 use std::mem;
+use iana::{Opcode, Rcode};
 use super::error::{ComposeError, ComposeResult};
-use super::iana::{Opcode, Rcode};
 
 
 //------------ Header --------------------------------------------------
@@ -541,7 +541,7 @@ impl FullHeader {
 #[cfg(test)]
 mod test {
     use super::*;
-    use super::super::iana::{Opcode, Rcode};
+    use iana::{Opcode, Rcode};
 
     macro_rules! test_field {
         ($get:ident, $set:ident, $default:expr, $($value:expr),*) => {
diff --git a/src/bits/message.rs b/src/bits/message.rs
index 973990d9..c60243c2 100644
--- a/src/bits/message.rs
+++ b/src/bits/message.rs
@@ -11,11 +11,11 @@ use std::collections::HashMap;
 use std::marker::PhantomData;
 use std::mem;
 use std::ops::{Deref, DerefMut};
+use iana::{Class, Rcode, RRType};
 use rdata::CName;
 use super::compose::{ComposeBytes, ComposeBuf};
 use super::error::{ComposeError, ComposeResult, ParseError, ParseResult};
 use super::header::{Header, HeaderCounts, FullHeader};
-use super::iana::{Class, Rcode, RRType};
 use super::name::{AsDName, DNameSlice};
 use super::parse::{ContextParser, ParseBytes};
 use super::question::{Question, QuestionTarget};
@@ -1118,9 +1118,9 @@ impl<C: ComposeBytes> MessageTarget<C> {
 mod test {
     use std::str::FromStr;
     use bits::name::DName;
-    use bits::iana::{Class, RRType};
     use bits::question::Question;
     use bits::record::Record;
+    use iana::{Class, RRType};
     use rdata::{A, CName};
     use super::*;
 
diff --git a/src/bits/mod.rs b/src/bits/mod.rs
index a239cba6..2fd97a0b 100644
--- a/src/bits/mod.rs
+++ b/src/bits/mod.rs
@@ -38,7 +38,6 @@ pub use self::charstr::{CharStr, CharStrError};
 pub use self::compose::{ComposeBytes, ComposeBuf};
 pub use self::error::{ComposeError, ComposeResult, ParseError, ParseResult,
                       FromStrError, FromStrResult};
-pub use self::iana::{Class, Opcode, Rcode, RRType};
 pub use self::message::{Message, MessageBuf, MessageBuilder};
 pub use self::name::{AsDName, DName, DNameSlice, DNameBuf, PackedDName};
 pub use self::nest::Nest;
@@ -52,7 +51,6 @@ pub mod charstr;
 pub mod compose;
 pub mod error;
 pub mod header;
-pub mod iana;
 pub mod message;
 pub mod name;
 pub mod nest;
diff --git a/src/bits/question.rs b/src/bits/question.rs
index acaa8353..cddfb266 100644
--- a/src/bits/question.rs
+++ b/src/bits/question.rs
@@ -4,9 +4,9 @@
 //! the question section of a DNS message.
 
 use std::fmt;
+use iana::{Class, RRType};
 use super::compose::ComposeBytes;
 use super::error::{ComposeResult, ParseResult};
-use super::iana::{Class, RRType};
 use super::name::{AsDName, DName};
 use super::parse::ParseBytes;
 
diff --git a/src/bits/rdata.rs b/src/bits/rdata.rs
index 41bb48aa..cb6f6579 100644
--- a/src/bits/rdata.rs
+++ b/src/bits/rdata.rs
@@ -13,9 +13,9 @@
 //! type that can deal with all record types.
 
 use std::fmt;
+use iana::RRType;
 use super::compose::ComposeBytes;
 use super::error::{ComposeResult, ParseResult};
-use super::iana::RRType;
 use super::nest::Nest;
 use super::parse::ParseBytes;
 
diff --git a/src/bits/record.rs b/src/bits/record.rs
index d574eb21..fbe39dbe 100644
--- a/src/bits/record.rs
+++ b/src/bits/record.rs
@@ -3,9 +3,9 @@
 //! This module defines the type `Record` that represents a resource record.
 
 use std::fmt;
+use iana::{Class, RRType};
 use super::compose::ComposeBytes;
 use super::error::{ComposeError, ComposeResult, ParseResult};
-use super::iana::{Class, RRType};
 use super::name::{AsDName, DName};
 use super::parse::ParseBytes;
 use super::rdata::RecordData;
diff --git a/src/bits/iana/class.rs b/src/iana/class.rs
similarity index 99%
rename from src/bits/iana/class.rs
rename to src/iana/class.rs
index 85798b1b..d957166e 100644
--- a/src/bits/iana/class.rs
+++ b/src/iana/class.rs
@@ -5,7 +5,7 @@ use std::convert;
 use std::fmt;
 use std::hash;
 use std::str;
-use super::super::error::{FromStrError, FromStrResult};
+use bits::error::{FromStrError, FromStrResult};
 
 
 //------------ Class --------------------------------------------------------
diff --git a/src/bits/iana/mod.rs b/src/iana/mod.rs
similarity index 100%
rename from src/bits/iana/mod.rs
rename to src/iana/mod.rs
diff --git a/src/bits/iana/opcode.rs b/src/iana/opcode.rs
similarity index 100%
rename from src/bits/iana/opcode.rs
rename to src/iana/opcode.rs
diff --git a/src/bits/iana/opt.rs b/src/iana/opt.rs
similarity index 100%
rename from src/bits/iana/opt.rs
rename to src/iana/opt.rs
diff --git a/src/bits/iana/rcode.rs b/src/iana/rcode.rs
similarity index 100%
rename from src/bits/iana/rcode.rs
rename to src/iana/rcode.rs
diff --git a/src/bits/iana/rrtype.rs b/src/iana/rrtype.rs
similarity index 99%
rename from src/bits/iana/rrtype.rs
rename to src/iana/rrtype.rs
index 83cec794..3b853d26 100644
--- a/src/bits/iana/rrtype.rs
+++ b/src/iana/rrtype.rs
@@ -6,7 +6,7 @@ use std::convert;
 use std::fmt;
 use std::hash;
 use std::str;
-use super::super::error::{FromStrError, FromStrResult};
+use bits::error::{FromStrError, FromStrResult};
 
 
 /// Resource Record Types.
diff --git a/src/lib.rs b/src/lib.rs
index daaa1cf8..f38124e6 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -13,12 +13,8 @@ extern crate rand;
 extern crate rotor;
 extern crate vecio;
 
-/*
-#[macro_use]
-mod macros;
-*/
-
 pub mod bits;
+pub mod iana;
 pub mod rdata;
 pub mod resolv;
 
diff --git a/src/rdata/rfc1035.rs b/src/rdata/rfc1035.rs
index c2f1cf32..72a3be05 100644
--- a/src/rdata/rfc1035.rs
+++ b/src/rdata/rfc1035.rs
@@ -8,7 +8,7 @@ use std::net::Ipv4Addr;
 use bits::compose::ComposeBytes;
 use bits::charstr::CharStr;
 use bits::error::{ComposeResult, ParseResult};
-use bits::iana::{Class, RRType};
+use iana::{Class, RRType};
 use bits::name::{AsDName, DName};
 use bits::octets::Octets;
 use bits::parse::ParseBytes;
diff --git a/src/rdata/rfc3596.rs b/src/rdata/rfc3596.rs
index 6a7a7a02..6ca9d429 100644
--- a/src/rdata/rfc3596.rs
+++ b/src/rdata/rfc3596.rs
@@ -6,7 +6,7 @@ use std::fmt;
 use std::net::Ipv6Addr;
 use bits::compose::ComposeBytes;
 use bits::error::{ComposeResult, ParseResult};
-use bits::iana::RRType;
+use iana::RRType;
 use bits::parse::ParseBytes;
 use bits::rdata::RecordData;
 
diff --git a/src/rdata/rfc6891.rs b/src/rdata/rfc6891.rs
new file mode 100644
index 00000000..0a47fd83
--- /dev/null
+++ b/src/rdata/rfc6891.rs
@@ -0,0 +1,14 @@
+//! Record data from RFC 6891.
+//!
+//! This RFC contains the currently valid definition of the OPT resouce
+//! record type originally defined in RFC 2671.
+//!
+//! OPT records actually requisition some of the fields of a DNS record for
+//! their own purpose. Because of this, this module does not only define
+//! the `Opt` type for the OPT resource data but also `OptRecord` for an
+//! entire OPT record.
+
+
+//------------ Opt ----------------------------------------------------------
+
+
diff --git a/src/resolv/tasks/addr.rs b/src/resolv/tasks/addr.rs
index a1fbb3de..53c23570 100644
--- a/src/resolv/tasks/addr.rs
+++ b/src/resolv/tasks/addr.rs
@@ -2,8 +2,9 @@
 
 use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};
 use std::str::FromStr;
-use bits::{AsDName, Class, DName, DNameBuf, MessageBuf, Question, RRType};
+use bits::{AsDName, DName, DNameBuf, MessageBuf, Question};
 use bits::name::Label;
+use iana::{Class, RRType};
 use rdata::Ptr;
 use resolv::Error;
 use resolv::tasks::traits::{Progress, Task, TaskRunner};
diff --git a/src/resolv/tasks/host.rs b/src/resolv/tasks/host.rs
index deeed1bf..24172276 100644
--- a/src/resolv/tasks/host.rs
+++ b/src/resolv/tasks/host.rs
@@ -2,8 +2,9 @@
 
 use std::net::IpAddr;
 use std::slice;
-use bits::{AsDName, Class, DName, DNameBuf, DNameSlice, MessageBuf, ParseResult,
-           Question, RecordData, RRType};
+use bits::{AsDName, DName, DNameBuf, DNameSlice, MessageBuf, ParseResult,
+           Question, RecordData};
+use iana::{Class, RRType};
 use rdata::{A, AAAA};
 use resolv::conf::ResolvConf;
 use resolv::tasks::traits::{Progress, Task, TaskRunner};
diff --git a/src/resolv/tasks/query.rs b/src/resolv/tasks/query.rs
index ae49302b..b8bc22b3 100644
--- a/src/resolv/tasks/query.rs
+++ b/src/resolv/tasks/query.rs
@@ -1,6 +1,7 @@
 //! A task for a simple, raw DNS query.
 
-use bits::{Class, DName, MessageBuf, Question, RRType};
+use bits::{DName, MessageBuf, Question};
+use iana::{Class, RRType};
 use resolv::error::Error;
 use resolv::tasks::traits::{Progress, Task, TaskRunner};
 
diff --git a/src/resolv/tasks/traits.rs b/src/resolv/tasks/traits.rs
index 2ea18b15..4c50fcbd 100644
--- a/src/resolv/tasks/traits.rs
+++ b/src/resolv/tasks/traits.rs
@@ -34,7 +34,8 @@
 //! let go of references as soon as the task has been started, avoiding
 //! having to clone the domain name.
 
-use bits::{Class, DName, MessageBuf, Question, RRType};
+use bits::{DName, MessageBuf, Question};
+use iana::{Class, RRType};
 use resolv::error::Error;
 
 //------------ Progress -----------------------------------------------------