diff --git a/CHANGES.md b/CHANGES.md
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -2,6 +2,14 @@
 ==========
 <!-- Append new entries here -->
 
+1.15.1
+======
+* [!879](https://gitlab.com/morley-framework/morley/-/merge_requests/879)
+  + Add Buildable and RenderDoc instances for `Instr inp out` type.
+  + Instances are based on transforming `Instr inp out` to list of `ExpandedOp` and using its instance
+* [!900](https://gitlab.com/morley-framework/morley/-/merge_requests/900)
+  + Added clarification that "OCaml reference client" is `tezos-client`.
+
 1.15.0
 ======
 * [!878](https://gitlab.com/morley-framework/morley/-/merge_requests/878)
@@ -14,7 +22,7 @@
   + Fixed loss of type annotations in serialization of right-combed pairs.
 * [!795](https://gitlab.com/morley-framework/morley/-/merge_requests/795)
   + Changed typecheck exception messages.
-  +  Changed Buildable instances for several datatypes to be based on
+  + Changed Buildable instances for several datatypes to be based on
      RenderDoc instances.
   + Changed the regexp in scripts/regenerate-gold-files-for-verbose-typechecking.sh
     so it does not ommit extra space in .gold files on MacOS.
diff --git a/app/Main.hs b/app/Main.hs
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -124,7 +124,7 @@
              <*> (#output <.?> outputOption)
              <*> (#singleLine <.!> onelineOption))
       ("Parse a Morley contract and print corresponding Michelson " <>
-       "contract that can be parsed by the OCaml reference client")
+       "contract that can be parsed by the OCaml reference client: tezos-client")
 
     runSubCmd =
       mkCommandParser "run"
diff --git a/docs/language/morleyLanguage.md b/docs/language/morleyLanguage.md
--- a/docs/language/morleyLanguage.md
+++ b/docs/language/morleyLanguage.md
@@ -9,7 +9,7 @@
 The Morley Language is a low-level syntactic sugar over the core Michelson
 instructions (core Michelson being the instructions which are actually executed
 in the Tezos blockchain, as opposed to the various syntactic conveniences
-provided by the OCaml reference client).
+provided by the OCaml reference client: `tezos-client`).
 
 The general principle is that any syntactically valid core Michelson expression
 will also be a valid Morley expression, i.e. Morley is a superset of
diff --git a/morley.cabal b/morley.cabal
--- a/morley.cabal
+++ b/morley.cabal
@@ -5,7 +5,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           morley
-version:        1.15.0
+version:        1.15.1
 synopsis:       Developer tools for the Michelson Language
 description:    A library to make writing smart contracts in Michelson — the smart contract language of the Tezos blockchain — pleasant and effective.
 category:       Language
diff --git a/src/Michelson/Macro.hs b/src/Michelson/Macro.hs
--- a/src/Michelson/Macro.hs
+++ b/src/Michelson/Macro.hs
@@ -41,7 +41,6 @@
 import Data.Data (Data(..))
 import qualified Data.Text as T
 import Fmt (Buildable(build), genericF, (+|), (+||), (|+), (||+))
-import qualified Text.PrettyPrint.Leijen.Text as PP (empty)
 
 import Michelson.ErrorPos
 import Michelson.Printer (RenderDoc(..))
@@ -101,9 +100,8 @@
   | Seq [ParsedOp]   SrcPos -- ^ A sequence of instructions
   deriving stock (Eq, Show, Data, Generic)
 
--- dummy value
 instance RenderDoc ParsedOp where
-  renderDoc _ _ = PP.empty
+  renderDoc pn parsedOp = renderDoc pn $ expand [] parsedOp
 
 instance Buildable ParsedOp where
   build = \case
diff --git a/src/Michelson/Optimizer.hs b/src/Michelson/Optimizer.hs
--- a/src/Michelson/Optimizer.hs
+++ b/src/Michelson/Optimizer.hs
@@ -30,7 +30,7 @@
   , ocGotoValuesL
   ) where
 
-import Prelude hiding (EQ)
+import Prelude hiding (EQ, LT, GT)
 
 import Control.Lens (makeLensesFor)
 import Data.Constraint (Dict(..))
@@ -118,6 +118,7 @@
     `orSimpleRule` pairUnpair
     `orSimpleRule` unpairMisc
     `orSimpleRule` swapBeforeCommutative
+    `orSimpleRule` justDrops
 
 -- | We do not enable 'pushPack' rule by default because it is
 -- potentially dangerous.
@@ -165,24 +166,52 @@
 
 variousNops :: Rule
 variousNops = \case
-  SWAP      :# SWAP :# c -> Just c
-  PUSH _    :# DROP :# c -> Just c
-  DUP       :# DROP :# c -> Just c
-  UNIT      :# DROP :# c -> Just c
-  NOW       :# DROP :# c -> Just c
-  SENDER    :# DROP :# c -> Just c
-  EMPTY_MAP :# DROP :# c -> Just c
-  EMPTY_SET :# DROP :# c -> Just c
+  DUP                :# DROP :# c -> Just c
+  DUPN _             :# DROP :# c -> Just c
+  SWAP               :# SWAP :# c -> Just c
+  PUSH _             :# DROP :# c -> Just c
+  NONE               :# DROP :# c -> Just c
+  UNIT               :# DROP :# c -> Just c
+  NIL                :# DROP :# c -> Just c
+  EMPTY_SET          :# DROP :# c -> Just c
+  EMPTY_MAP          :# DROP :# c -> Just c
+  EMPTY_BIG_MAP      :# DROP :# c -> Just c
+  LAMBDA _           :# DROP :# c -> Just c
+  SELF _             :# DROP :# c -> Just c
+  NOW                :# DROP :# c -> Just c
+  AMOUNT             :# DROP :# c -> Just c
+  BALANCE            :# DROP :# c -> Just c
+  TOTAL_VOTING_POWER :# DROP :# c -> Just c
+  SOURCE             :# DROP :# c -> Just c
+  SENDER             :# DROP :# c -> Just c
+  CHAIN_ID           :# DROP :# c -> Just c
+  LEVEL              :# DROP :# c -> Just c
+  SELF_ADDRESS       :# DROP :# c -> Just c
+  READ_TICKET        :# DROP :# c -> Just c
 
-  SWAP      :# SWAP      -> Just Nop
-  PUSH _    :# DROP      -> Just Nop
-  DUP       :# DROP      -> Just Nop
-  UNIT      :# DROP      -> Just Nop
-  NOW       :# DROP      -> Just Nop
-  SENDER    :# DROP      -> Just Nop
-  EMPTY_MAP :# DROP      -> Just Nop
-  EMPTY_SET :# DROP      -> Just Nop
-  _                      -> Nothing
+  DUP                :# DROP -> Just Nop
+  DUPN _             :# DROP -> Just Nop
+  SWAP               :# SWAP -> Just Nop
+  PUSH _             :# DROP -> Just Nop
+  NONE               :# DROP -> Just Nop
+  UNIT               :# DROP -> Just Nop
+  NIL                :# DROP -> Just Nop
+  EMPTY_SET          :# DROP -> Just Nop
+  EMPTY_MAP          :# DROP -> Just Nop
+  EMPTY_BIG_MAP      :# DROP -> Just Nop
+  LAMBDA _           :# DROP -> Just Nop
+  SELF _             :# DROP -> Just Nop
+  NOW                :# DROP -> Just Nop
+  AMOUNT             :# DROP -> Just Nop
+  BALANCE            :# DROP -> Just Nop
+  TOTAL_VOTING_POWER :# DROP -> Just Nop
+  SOURCE             :# DROP -> Just Nop
+  SENDER             :# DROP -> Just Nop
+  CHAIN_ID           :# DROP -> Just Nop
+  LEVEL              :# DROP -> Just Nop
+  SELF_ADDRESS       :# DROP -> Just Nop
+  READ_TICKET        :# DROP -> Just Nop
+  _                          -> Nothing
 
 dupSwap2dup :: Rule
 dupSwap2dup = \case
@@ -359,6 +388,9 @@
 
   DUP :# CDR :# DIP CAR      -> Just $ UNPAIR :# SWAP
   DUP :# CDR :# DIP CAR :# c -> Just $ UNPAIR :# SWAP :# c
+
+  UNPAIR :# DROP             -> Just CDR
+  UNPAIR :# DROP :# c        -> Just $ CDR :# c
   _ -> Nothing
 
 commuteArith ::
@@ -387,6 +419,83 @@
   where
     pushPacked :: PackedValScope t => Value t -> Instr s ('TBytes ': s)
     pushPacked = PUSH . VBytes . packValue'
+
+justDrops :: Rule
+justDrops = \case
+  CAR              :# DROP :# c -> Just $ DROP :# c
+  CDR              :# DROP :# c -> Just $ DROP :# c
+  SOME             :# DROP :# c -> Just $ DROP :# c
+  LEFT             :# DROP :# c -> Just $ DROP :# c
+  RIGHT            :# DROP :# c -> Just $ DROP :# c
+  SIZE             :# DROP :# c -> Just $ DROP :# c
+  GETN _           :# DROP :# c -> Just $ DROP :# c
+  CAST             :# DROP :# c -> Just $ DROP :# c
+  RENAME           :# DROP :# c -> Just $ DROP :# c
+  PACK             :# DROP :# c -> Just $ DROP :# c
+  UNPACK           :# DROP :# c -> Just $ DROP :# c
+  CONCAT'          :# DROP :# c -> Just $ DROP :# c
+  ISNAT            :# DROP :# c -> Just $ DROP :# c
+  ABS              :# DROP :# c -> Just $ DROP :# c
+  NEG              :# DROP :# c -> Just $ DROP :# c
+  NOT              :# DROP :# c -> Just $ DROP :# c
+  EQ               :# DROP :# c -> Just $ DROP :# c
+  NEQ              :# DROP :# c -> Just $ DROP :# c
+  LT               :# DROP :# c -> Just $ DROP :# c
+  GT               :# DROP :# c -> Just $ DROP :# c
+  LE               :# DROP :# c -> Just $ DROP :# c
+  GE               :# DROP :# c -> Just $ DROP :# c
+  INT              :# DROP :# c -> Just $ DROP :# c
+  CONTRACT _ _     :# DROP :# c -> Just $ DROP :# c
+  SET_DELEGATE     :# DROP :# c -> Just $ DROP :# c
+  IMPLICIT_ACCOUNT :# DROP :# c -> Just $ DROP :# c
+  VOTING_POWER     :# DROP :# c -> Just $ DROP :# c
+  SHA256           :# DROP :# c -> Just $ DROP :# c
+  SHA512           :# DROP :# c -> Just $ DROP :# c
+  BLAKE2B          :# DROP :# c -> Just $ DROP :# c
+  SHA3             :# DROP :# c -> Just $ DROP :# c
+  KECCAK           :# DROP :# c -> Just $ DROP :# c
+  HASH_KEY         :# DROP :# c -> Just $ DROP :# c
+  PAIRING_CHECK    :# DROP :# c -> Just $ DROP :# c
+  ADDRESS          :# DROP :# c -> Just $ DROP :# c
+  JOIN_TICKETS     :# DROP :# c -> Just $ DROP :# c
+
+  CAR              :# DROP      -> Just DROP
+  CDR              :# DROP      -> Just DROP
+  SOME             :# DROP      -> Just DROP
+  LEFT             :# DROP      -> Just DROP
+  RIGHT            :# DROP      -> Just DROP
+  SIZE             :# DROP      -> Just DROP
+  GETN _           :# DROP      -> Just DROP
+  CAST             :# DROP      -> Just DROP
+  RENAME           :# DROP      -> Just DROP
+  PACK             :# DROP      -> Just DROP
+  UNPACK           :# DROP      -> Just DROP
+  CONCAT'          :# DROP      -> Just DROP
+  ISNAT            :# DROP      -> Just DROP
+  ABS              :# DROP      -> Just DROP
+  NEG              :# DROP      -> Just DROP
+  NOT              :# DROP      -> Just DROP
+  EQ               :# DROP      -> Just DROP
+  NEQ              :# DROP      -> Just DROP
+  LT               :# DROP      -> Just DROP
+  GT               :# DROP      -> Just DROP
+  LE               :# DROP      -> Just DROP
+  GE               :# DROP      -> Just DROP
+  INT              :# DROP      -> Just DROP
+  CONTRACT _ _     :# DROP      -> Just DROP
+  SET_DELEGATE     :# DROP      -> Just DROP
+  IMPLICIT_ACCOUNT :# DROP      -> Just DROP
+  VOTING_POWER     :# DROP      -> Just DROP
+  SHA256           :# DROP      -> Just DROP
+  SHA512           :# DROP      -> Just DROP
+  BLAKE2B          :# DROP      -> Just DROP
+  SHA3             :# DROP      -> Just DROP
+  KECCAK           :# DROP      -> Just DROP
+  HASH_KEY         :# DROP      -> Just DROP
+  PAIRING_CHECK    :# DROP      -> Just DROP
+  ADDRESS          :# DROP      -> Just DROP
+  JOIN_TICKETS     :# DROP      -> Just DROP
+  _                             -> Nothing
 
 -- | Append LHS of 'Seq' to RHS and re-run pointwise ocRuleset at each point.
 --   That might cause reinvocation of this function (see 'defaultRules'),
diff --git a/src/Michelson/Printer.hs b/src/Michelson/Printer.hs
--- a/src/Michelson/Printer.hs
+++ b/src/Michelson/Printer.hs
@@ -23,24 +23,24 @@
 import qualified Michelson.Untyped as U
 
 -- | Convert an untyped contract into a textual representation which
--- will be accepted by the OCaml reference client.
+-- will be accepted by the OCaml reference client: tezos-client.
 printUntypedContract :: (RenderDoc op) => Bool -> U.Contract' op -> TL.Text
 printUntypedContract forceSingleLine = printDoc forceSingleLine . renderDoc doesntNeedParens
 
 -- | Convert a typed contract into a textual representation which
--- will be accepted by the OCaml reference client.
+-- will be accepted by the OCaml reference client: tezos-client.
 printTypedContractCode :: (SingI p, SingI s) => Bool -> T.ContractCode p s -> TL.Text
 printTypedContractCode forceSingleLine =
   printUntypedContract forceSingleLine . T.convertContractCode
 
 -- | Convert typed contract into a textual representation which
--- will be accepted by the OCaml reference client.
+-- will be accepted by the OCaml reference client: tezos-client.
 printTypedContract :: Bool -> T.Contract p s -> TL.Text
 printTypedContract forceSingleLine fc@T.Contract{} =
   printUntypedContract forceSingleLine $ T.convertContract fc
 
 -- | Convert typed value into a textual representation which
--- will be accepted by the OCaml reference client.
+-- will be accepted by the OCaml reference client: tezos-client.
 printTypedValue
   :: forall t.
       (T.ProperPrintedValBetterErrors t)
@@ -50,13 +50,13 @@
   printUntypedValue forceSingleLine . T.untypeValue
 
 -- | Convert untyped value into a textual representation which
--- will be accepted by the OCaml reference client.
+-- will be accepted by the OCaml reference client: tezos-client.
 printUntypedValue :: (RenderDoc op) => Bool -> U.Value' op -> TL.Text
 printUntypedValue forceSingleLine =
   printDoc forceSingleLine . renderDoc doesntNeedParens
 
 -- | Convert 'SomeContract' into a textual representation which
--- will be accepted by the OCaml reference client.
+-- will be accepted by the OCaml reference client: tezos-client.
 printSomeContract :: Bool -> T.SomeContract -> TL.Text
 printSomeContract forceSingleLine (T.SomeContract fc) =
   printTypedContract forceSingleLine fc
diff --git a/src/Michelson/Runtime/Dummy.hs b/src/Michelson/Runtime/Dummy.hs
--- a/src/Michelson/Runtime/Dummy.hs
+++ b/src/Michelson/Runtime/Dummy.hs
@@ -27,7 +27,7 @@
 dummyNow = Timestamp 100
 
 dummyLevel :: Natural
-dummyLevel = 0
+dummyLevel = 4000
 
 -- | Dummy value for maximal number of steps a contract can
 -- make. Intentionally quite large, because most likely if you use
diff --git a/src/Michelson/Typed/Convert.hs b/src/Michelson/Typed/Convert.hs
--- a/src/Michelson/Typed/Convert.hs
+++ b/src/Michelson/Typed/Convert.hs
@@ -30,6 +30,7 @@
 import Data.Vinyl (Rec(..))
 import Fmt (Buildable(..), Builder, blockListF, fmt, indentF, listF, pretty, unlinesF)
 
+
 import Michelson.Text
 import Michelson.Typed.Aliases
 import Michelson.Typed.Annotation (Notes(..))
@@ -40,6 +41,7 @@
 import Michelson.Typed.Sing (SingT(..))
 import Michelson.Typed.T (T(..))
 import Michelson.Typed.Value
+import Michelson.Printer.Util
 import qualified Michelson.Untyped as U
 import Michelson.Untyped.Annotation (Annotation(unAnnotation))
 import Tezos.Address (Address(..), ContractHash(..))
@@ -761,6 +763,12 @@
 
 instance (SingI t, HasNoOp t) => Buildable (Value' Instr t) where
   build = build . untypeValue
+
+instance Buildable (Instr inp out) where
+  build = buildRenderDocExtended
+
+instance RenderDoc (Instr inp out) where
+  renderDoc context = renderDocList context . instrToOps
 
 -- | Generate a value used for generating examples in documentation.
 --
diff --git a/src/Michelson/Typed/Sing.hs b/src/Michelson/Typed/Sing.hs
--- a/src/Michelson/Typed/Sing.hs
+++ b/src/Michelson/Typed/Sing.hs
@@ -5,6 +5,7 @@
 {-# LANGUAGE StandaloneKindSignatures #-}
 {-# OPTIONS_GHC -Wno-unused-top-binds #-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
+{-# OPTIONS_GHC -Wno-redundant-constraints #-}
 
 -- | Module, providing singleton boilerplate for
 -- 'T' data types.
diff --git a/src/Morley/Micheline/Class.hs b/src/Morley/Micheline/Class.hs
--- a/src/Morley/Micheline/Class.hs
+++ b/src/Morley/Micheline/Class.hs
@@ -798,9 +798,9 @@
       let va1 = firstAnn @VarTag as1
       let va2 = firstAnn @VarTag as2
       l <- fromExpression $ removeAnns arg1
-        (liftA2 (||) isAnnotationField isAnnotationVariable)
+        (isAnnotationField || isAnnotationVariable)
       r <- fromExpression $ removeAnns arg2
-        (liftA2 (||) isAnnotationField isAnnotationVariable)
+        (isAnnotationField || isAnnotationVariable)
       pure $ Untyped.TPair fa1 fa2 va1 va2 l r
     PrimExpr "pair" args [] ->
       case (nonEmpty args) >>= forbidSingletonList of
diff --git a/src/Util/PeanoNatural.hs b/src/Util/PeanoNatural.hs
--- a/src/Util/PeanoNatural.hs
+++ b/src/Util/PeanoNatural.hs
@@ -18,9 +18,12 @@
   ) where
 
 import Data.Singletons (SingI (..))
+import Text.PrettyPrint.Leijen.Text (integer)
 import Util.Peano (Nat (Z, S), SingNat(..), ToPeano)
 import qualified GHC.TypeNats as GHC (Nat)
 
+import Michelson.Printer.Util
+
 -- | PeanoNatural data type
 --
 -- The @PN@ constructor stores @s :: SingNat n@ and @k :: Natural@
@@ -32,6 +35,9 @@
 
 deriving stock instance Show (PeanoNatural n)
 deriving stock instance Eq (PeanoNatural n)
+
+instance RenderDoc (PeanoNatural n) where
+  renderDoc _ = integer . toInteger . fromPeanoNatural
 
 instance NFData (PeanoNatural n) where
   rnf (PN s _) = rnf s