diff --git a/docs/conf.py b/docs/conf.py
index 22037d5..a355b8d 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -15,7 +15,7 @@
 import os
 import sys
 sys.path.insert(0, os.path.abspath('..'))
-VERSION = "Electrum Protocol 1.4.x"
+VERSION = "Electrum Protocol 1.6.x"
 
 # -- Project information -----------------------------------------------------
 
diff --git a/docs/protocol-basics.rst b/docs/protocol-basics.rst
index ffdfee7..5b9869c 100644
--- a/docs/protocol-basics.rst
+++ b/docs/protocol-basics.rst
@@ -68,14 +68,12 @@ revision number.
 
 A party to a connection will speak all protocol versions in a range,
 say from `protocol_min` to `protocol_max`, which may be the same.
-When a connection is made, both client and server must initially
-assume the protocol to use is their own `protocol_min`.
 
-The client should send a :func:`server.version` RPC call as early as
-possible in order to negotiate the precise protocol version; see its
-description for more detail.  All responses received in the stream
-from and including the server's response to this call will use its
-negotiated protocol version.
+The client must send a :func:`server.version` RPC call as the first
+message on the wire, in order to negotiate the precise protocol
+version; see its description for more detail.
+All responses received in the stream from and including the server's
+response to this call will use its negotiated protocol version.
 
 
 .. _script hashes:
@@ -144,27 +142,81 @@ Status
 To calculate the `status` of a :ref:`script hash <script hashes>` (or
 address):
 
-1. order confirmed transactions to the script hash by increasing
-height (and position in the block if there are more than one in a
-block)
+1. Consider all transactions touching the script hash (both those spending
+from it, and those funding it), both confirmed and unconfirmed (in mempool).
 
-2. form a string that is the concatenation of strings
+2. Order confirmed transactions by increasing height (and position in the
+block if there are more than one in a block).
+
+3. form a string that is the concatenation of strings
 ``"tx_hash:height:"`` for each transaction in order, where:
 
   * ``tx_hash`` is the transaction hash in hexadecimal
 
   * ``height`` is the height of the block it is in.
 
-3. Next, with mempool transactions in any order, append a similar
-string for those transactions, but where **height** is ``-1`` if the
-transaction has at least one unconfirmed input, and ``0`` if all
-inputs are confirmed.
+4. For mempool transactions, we define **height** to be ``-1`` if the
+transaction has at least one unconfirmed input, and ``0`` if all inputs are
+confirmed.
+
+5. Order mempool transactions by ``(-height, tx_hash)``, that is,
+``0`` height txs come before ``-1`` height txs, and secondarily the
+txid (in network byteorder) is used to arrive at a canonical ordering.
+
+6. Next, with mempool transactions in the specified order, append a similar
+string.
 
-4. The :dfn:`status` of the script hash is the :func:`sha256` hash of the
+7. The :dfn:`status` of the script hash is the :func:`sha256` hash of the
 full string expressed as a hexadecimal string, or :const:`null` if the
 string is empty because there are no transactions.
 
 
+**Status Example**
+
+Consider the following BTC regtest address: `bcrt1qwu2d7rjn9yxalg7cjw6phqzk77lf3fmsf57wq4`,
+which has script hash: `76bbdc72fdc74fbb0b049d21b0f80045f2a227cde1cd57a00925a437638984b5`.
+
+Example RPC traffic::
+
+    <-- ('blockchain.scripthash.subscribe', ['76bbdc72fdc74fbb0b049d21b0f80045f2a227cde1cd57a00925a437638984b5']) (id: 15)
+    --> 3b3b8f1bf926bde2e8e21d80b7d23afbef8f8ef697e7e9204683d9a29801b671 (id: 15)
+    <-- ('blockchain.scripthash.get_history', ['76bbdc72fdc74fbb0b049d21b0f80045f2a227cde1cd57a00925a437638984b5']) (id: 16)
+    --> [
+         {'tx_hash': '5c75485491ef13ca39c06a6c985de5223ac34a365fe26d461e567521f87bb378', 'height': 1860},
+         {'tx_hash': '9a2808f0cebab7fd71033b2974ab476098f8a6deb972b72fed60878a44badeda', 'height': 1861},
+         {'tx_hash': '07ec1e1dd23e337d55c7e21e892cca4d328cef5d6eddf29e59587e9056e891f7', 'height': 1861},
+         {'tx_hash': '98edd636bf8142d9ec0b88de3c8dbd3eb3da9bcfb02f7496f21408d8c6be58f2', 'height': 0, 'fee': 200},
+         {'tx_hash': '73fe76fe862413b8ff0f74b72c65c21fa1229a07d0625d994028363aa7cd58f7', 'height': 0, 'fee': 200},
+         {'tx_hash': 'b870b52ab5ecc3c3133ef1b9fff54d8d49c9c3ab7aa4236bf4c8d734d4d3b231', 'height': -1, 'fee': 110}
+         ] (id: 16)
+    <-- ('blockchain.transaction.get', ['5c75485491ef13ca39c06a6c985de5223ac34a365fe26d461e567521f87bb378']) (id: 17)
+    <-- ('blockchain.transaction.get', ['9a2808f0cebab7fd71033b2974ab476098f8a6deb972b72fed60878a44badeda']) (id: 18)
+    <-- ('blockchain.transaction.get', ['07ec1e1dd23e337d55c7e21e892cca4d328cef5d6eddf29e59587e9056e891f7']) (id: 19)
+    <-- ('blockchain.transaction.get', ['98edd636bf8142d9ec0b88de3c8dbd3eb3da9bcfb02f7496f21408d8c6be58f2']) (id: 20)
+    <-- ('blockchain.transaction.get', ['73fe76fe862413b8ff0f74b72c65c21fa1229a07d0625d994028363aa7cd58f7']) (id: 21)
+    <-- ('blockchain.transaction.get', ['b870b52ab5ecc3c3133ef1b9fff54d8d49c9c3ab7aa4236bf4c8d734d4d3b231']) (id: 22)
+    --> 02000000000101887e2ea83a1fbface451aa3b2ba556757039bfe266d8b0c03383b2a6bc306a0b0000000000fdffffff0200e1f505000000001600147714df0e53290ddfa3d893b41b8056f7be98a77038b23f710000000016001496ea3197df375c6a62188cf9119aee984c0cc6150247304402206e1bbfca238613dbb5c877007273ddc708a5bdf0436e8e9df8cff4860937a64402200d86cc261234f5d448dd005c28a7bfc29d86b4d3004c76f5440aa662ba65479f01210242c23a20435cd52192581537b2017288b8cdf3fef349100c11a125d9529017e143070000 (id: 17)
+    --> 0200000000010178b37bf82175561e466de25f364ac33a22e55d986c6ac039ca13ef915448755c0100000000fdffffff0200e1f505000000001600147714df0e53290ddfa3d893b41b8056f7be98a77070d0496b00000000160014e5ec5a8eff827f8ab906f94026e83a7404b8bf860247304402200a6a2c21d2829d65e5439e3153a6b157e231942d3fa9b9d90b2567b1eec11851022036e4797a67bb1bbd1e2239ab51905db07bb5a31a3ac63b0eadbb8e5e27baf63d012103a23dcf3edc18180b0d82b0be8eb1c30ae61597e99e298246e05109b7ba89763744070000 (id: 18)
+    --> 02000000000101887e2ea83a1fbface451aa3b2ba556757039bfe266d8b0c03383b2a6bc306a0b0100000000fdffffff0200e1f505000000001600147714df0e53290ddfa3d893b41b8056f7be98a770c4b8004d3a000000160014692a676d16f83641a6518e9154d2b43a8465ed440247304402206578cda616dd7425b7f7cc35a67892361168275ac8a8ca0c6a3e1eefd595e9de02200466d0eb0a4ed4351ae806793151f5bfdae44904507efe4225a67f36ef2de76c0121030644479c1b8c106e2f0a495fe18dc45572b3413bda2db919c1fcf0f77f43241c44070000 (id: 19)
+    --> 02000000000101dadeba448a8760ed2fb772b9dea6f8986047ab74293b0371fdb7bacef008289a0100000000fdffffff0200e1f505000000001600147714df0e53290ddfa3d893b41b8056f7be98a770a8ee536500000000160014783997038ebfd28edef06a1e088e9fd905c48d61024730440220426b0570147156e19cd4c6eff02f49e11747dc74eaad0299d884740c0f05958302200c93e46a3db4686d576943c88274ddb43afbcd4c491867642c1a9c3fba8ca3bf012103e0e2b67a3e8244900fa916decb6a9d45787ebe15b882c7a065cd0151d298fb4e45070000 (id: 20)
+    --> 02000000000101f791e856907e58599ef2dd6e5def8c324dca2c891ee2c7557d333ed21d1eec070100000000fdffffff0200e1f505000000001600147714df0e53290ddfa3d893b41b8056f7be98a770fcd60a473a000000160014641837eaea0de6ed898e30ff6e093c566d790521024730440220143065381913b92b572b6fc6362f89517f0d411d19d23ba025f43885736fdf7602201176d0f5284c65023baa06d760810085e8d7e0835b9a64a8046ab3c883499357012102be2e344c2f49afa8d734a2f79a09827b038d2f8f6bfa77d5a2e077c22a3fd80a45070000 (id: 21)
+    --> 02000000000101f258bec6d80814f296742fb0cf9bdab33ebd8d3cde880becd94281bf36d6ed980000000000fdffffff0192e0f505000000001600147714df0e53290ddfa3d893b41b8056f7be98a770024730440220569e38b9034c5855b866a35a16d949d16b7b544aff9d6b02b6d2ca7ebbd9c3b2022074a7d230241335436a2df1380a4d7c5442424a9a56a02124f4a0b495e9de24b50121027ba4d3ee6471a985307a37d09eb9a0a73c1a31b57616fe3e53a3d6d45400251945070000 (id: 22)
+    <-- ('blockchain.transaction.get_merkle', ['5c75485491ef13ca39c06a6c985de5223ac34a365fe26d461e567521f87bb378', 1860]) (id: 23)
+    <-- ('blockchain.transaction.get_merkle', ['9a2808f0cebab7fd71033b2974ab476098f8a6deb972b72fed60878a44badeda', 1861]) (id: 24)
+    <-- ('blockchain.transaction.get_merkle', ['07ec1e1dd23e337d55c7e21e892cca4d328cef5d6eddf29e59587e9056e891f7', 1861]) (id: 25)
+    --> {'block_height': 1860, 'merkle': ['7df6810d7ac97c43cbfc2bdc6be10e26cd54ad34ab5e563fd8bde7f86ff36975'], 'pos': 1} (id: 23)
+    --> {'block_height': 1861, 'merkle': ['ac7d7a5d8932f565a2cf9cb103881bfc3bf7aa2f56ccbcdeb31e02c524ddfd0b', 'f7d333193f2e5c48c236db7c3eafd5d03f387a71c4f9b6056617faefcf3d44cf'], 'pos': 1} (id: 24)
+    --> {'block_height': 1861, 'merkle': ['07ec1e1dd23e337d55c7e21e892cca4d328cef5d6eddf29e59587e9056e891f7', '5441fd37bd00b55ff5f9ea1a8956d2f3ade17c7fb7a363e8000b3e7cb40ea135'], 'pos': 2} (id: 25)
+
+So, mined txs are first ordered by block height, but block 1861 needs a tie-breaker:
+the two txs there are ordered based on position in the block.
+
+The mempool txs are first ordered based on inverse-"height", but height 0 needs a tie-breaker:
+those two txs are ordered based on network-endian txid (`f2` comes before `f7`).
+
+Finally, the status is `3b3b8f1bf926bde2e8e21d80b7d23afbef8f8ef697e7e9204683d9a29801b671`.
+
+
 Block Headers
 -------------
 
diff --git a/docs/protocol-changes.rst b/docs/protocol-changes.rst
index d4d0abb..7b7c2ee 100644
--- a/docs/protocol-changes.rst
+++ b/docs/protocol-changes.rst
@@ -2,7 +2,7 @@
 Protocol Changes
 ================
 
-This documents lists changes made by protocol version.
+This document lists changes made by protocol version.
 
 Version 1.0
 ===========
@@ -175,3 +175,44 @@ New methods
 -----------
 
   * :func:`blockchain.name.get_value_proof` to resolve a name (with proof).  Name index coins (e.g. Namecoin) only.
+
+
+Version 1.5
+===========
+
+(this version number was skipped, no corresponding protocol is defined)
+
+
+.. _version 1.6:
+
+Version 1.6
+===========
+
+Changes
+-------
+
+  * Breaking change for the version negotiation: we now mandate that
+    the :func:`server.version` message must be the first message sent.
+    That is, version negotiation must happen before any other messages.
+  * Also for :func:`server.version`, the server must tolerate and ignore
+    extraneous arguments, to allow for extensions in future protocol versions.
+  * The status of a scripthash has its definition tightened in a
+    backwards-compatible way: mempool txs now have a canonical ordering
+    defined for the calculation (previously their order was undefined).
+  * :func:`blockchain.scripthash.get_mempool` previously did not define
+    an order for mempool transactions. We now mandate a specific ordering.
+  * Optional *mode* argument added to :func:`blockchain.estimatefee`.
+  * :func:`blockchain.block.headers` now returns headers as a list,
+    instead of a single concatenated hex string.
+
+New methods
+-----------
+
+  * :func:`blockchain.transaction.broadcast_package` to broadcast a package of transactions (submitpackage).
+  * :func:`mempool.get_info` to get more detailed and general relayfee info.
+
+Removed methods
+---------------
+
+  * :func:`blockchain.relayfee` is removed. The `minrelaytxfee` field
+    of the new :func:`mempool.get_info` RPC is a direct replacement.
diff --git a/docs/protocol-methods.rst b/docs/protocol-methods.rst
index 8c3dba2..e1d7cda 100644
--- a/docs/protocol-methods.rst
+++ b/docs/protocol-methods.rst
@@ -76,7 +76,7 @@ With *cp_height* 8::
 blockchain.block.headers
 ========================
 
-Return a concatenated chunk of block headers from the main chain.
+Return a chunk of block headers from the main chain.
 
 **Signature**
 
@@ -85,6 +85,8 @@ Return a concatenated chunk of block headers from the main chain.
   .. versionchanged:: 1.4
      *cp_height* parameter added
   .. versionchanged:: 1.4.1
+  .. versionchanged:: 1.6
+     response contains *headers* field instead of *hex*
 
   *start_height*
 
@@ -106,17 +108,16 @@ Return a concatenated chunk of block headers from the main chain.
   A dictionary with the following members:
 
   * *count*
-
     The number of headers returned, between zero and the number
     requested.  If the chain has not extended sufficiently far, only
     the available headers will be returned.  If more headers than
     *max* were requested at most *max* will be returned.
 
-  * *hex*
+  * *headers*
 
-    The binary block headers concatenated together in-order as a
-    hexadecimal string.  Starting with version 1.4.1, AuxPoW data (if present
-    in the original header) is truncated if *cp_height* is nonzero.
+    An array containing the binary block headers in-order; each header is a
+    hexadecimal string.  AuxPoW data (if present in the original header) is
+    truncated if *cp_height* is nonzero.
 
   * *max*
 
@@ -149,7 +150,11 @@ See :ref:`here <cp_height example>` for an example of *root* and
 
   {
     "count": 2,
-    "hex": "0100000000000000000000000000000000000000000000000000000000000000000000003ba3edfd7a7b12b27ac72c3e67768f617fc81bc3888a51323a9fb8aa4b1e5e4a29ab5f49ffff001d1dac2b7c010000006fe28c0ab6f1b372c1a6a246ae63f74f931e8365e15a089c68d6190000000000982051fd1e4ba744bbbe680e1fee14677ba1a3c3540bf7b1cdb606e857233e0e61bc6649ffff001d01e36299"
+    "headers":
+    [
+      "0100000000000000000000000000000000000000000000000000000000000000000000003ba3edfd7a7b12b27ac72c3e67768f617fc81bc3888a51323a9fb8aa4b1e5e4a29ab5f49ffff001d1dac2b7c",
+      "010000006fe28c0ab6f1b372c1a6a246ae63f74f931e8365e15a089c68d6190000000000982051fd1e4ba744bbbe680e1fee14677ba1a3c3540bf7b1cdb606e857233e0e61bc6649ffff001d01e36299"
+    ],
     "max": 2016
   }
 
@@ -161,12 +166,21 @@ be confirmed within a certain number of blocks.
 
 **Signature**
 
-  .. function:: blockchain.estimatefee(number)
+  .. function:: blockchain.estimatefee(number, mode=None)
+  .. versionchanged:: 1.6
+     *mode* argument added
 
   *number*
 
     The number of blocks to target for confirmation.
 
+  *mode*
+
+    A string to pass to the bitcoind *estimatesmartfee* RPC as the
+    *estimate_mode* parameter. Optional. If omitted, the corresponding
+    parameter to the bitcoind RPC is also omitted, i.e. the default
+    value is determined by bitcoind.
+
 **Result**
 
   The estimated transaction fee in whole coin units per kilobyte, as a
@@ -179,6 +193,11 @@ be confirmed within a certain number of blocks.
 
   0.00101079
 
+.. note:: This estimate typically comes from the Bitcoin daemon, which only updates
+  its estimate when new blocks are mined. The server is free to cache this internally
+  for performance reasons, however it SHOULD avoid sending stale estimates
+  by e.g. invalidating the cache before notifying clients of a new block header.
+
 
 blockchain.headers.subscribe
 ============================
@@ -234,31 +253,6 @@ Subscribe to receive block headers when a new block is found.
   block headers to acquire a consistent view of the chain state.
 
 
-blockchain.relayfee
-===================
-
-Feerates lower than this are considered zero fee and are not being
-relayed to the bitcoin network by the server.
-This feerate does not guarantee acceptance into the mempool of the server.
-
-**Signature**
-
-  .. function:: blockchain.relayfee()
-
-**Result**
-
-  The feerate in BTC/kvB, as a floating point number.
-
-**Example Results**
-
-::
-
-   1e-05
-
-::
-
-   0.0
-
 blockchain.scripthash.get_balance
 =================================
 
@@ -359,6 +353,8 @@ hashes>`.
 
   .. function:: blockchain.scripthash.get_mempool(scripthash)
   .. versionadded:: 1.1
+  .. versionchanged:: 1.6
+     results must be sorted (previously undefined order)
 
   *scripthash*
 
@@ -366,8 +362,9 @@ hashes>`.
 
 **Result**
 
-  A list of mempool transactions in arbitrary order.  Each mempool
-  transaction is a dictionary with the following keys:
+  A list of mempool transactions. The order is the same as when computing the
+  :ref:`status <status>` of the script hash.
+  Each mempool transaction is a dictionary with the following keys:
 
   * *height*
 
@@ -552,6 +549,103 @@ Protocol version 1.0 returning an error as the result:
 
   "258: txn-mempool-conflict"
 
+blockchain.transaction.broadcast_package
+========================================
+
+Broadcast a package of transactions to the network (submitpackage). The package must consist of a child with its parents,
+and none of the parents may depend on one another. The package must be topologically sorted,
+with the child being the last element in the array.
+
+**Signature**
+
+  .. function:: blockchain.transaction.broadcast_package(raw_txs, verbose=false)
+
+  *raw_txs*
+
+    An array of raw transactions, each as a hexadecimal string.
+
+  *verbose*
+
+    Whether a verbose coin-specific response is required.
+
+**Result**
+
+  If *verbose* is :const:`false`:
+
+    A dictionary with the following keys:
+
+    * `success`
+        * Type: bool
+        * Value: Indicating the result of the package submission
+    * `errors`
+        * Type: Optional[List[Dict]]
+        * Value: Error message and txid (NOT wtxid) of transactions that were not accepted
+
+  If *verbose* is :const:`true`:
+
+    The result is a bitcoind-specific dictionary -- whatever bitcoind
+    returns as response to the submitpackage (or equivalent) RPC.
+    (`example docs <https://bitcoincore.org/en/doc/30.0.0/rpc/rawtransactions/submitpackage/>`_ for Bitcoin Core)
+
+    As the exact structure and semantics depend on the bitcoind version (or alternative bitcoind, e.g. btcd),
+    the electrum protocol can make no guarantees about it.
+    Unlike the `verbose=False` result, which is guaranteed to be stable and can be relied upon,
+    the `verbose=True` result should be considered experimental and better-suited for debugging.
+
+.. note:: The exact relay behaviour might depend on the bitcoind version of the server.
+
+.. note:: Server implementations should verify (e.g. by enforcing a minimum bitcoind version at runtime)
+  that the backing bitcoind supports relay of transaction packages. For example, note that Bitcoin Core 26.0
+  already exposes the `submitpackage` RPC however it is effectively non-functional until Bitcoin Core 28.0.
+
+**Result Example**
+
+When *verbose* is :const:`false`::
+
+    {
+      "success": true
+    }
+
+    With errors:
+
+    {
+      "success": false,
+      "errors":
+      [
+        {
+          "txid": "ec6f295cd4b1b91f59cabb0ab8fdc7c76580db08be6426e465f75a69d82b9659",
+          "error": "bad-txns-inputs-missingorspent"
+        }
+      ]
+    }
+
+When *verbose* is :const:`true` (exact structure depends on bitcoind impl and version, and should not be relied upon)::
+
+    {                                   (json object)
+      "package_msg" : "str",            (string) The transaction package result message. "success" indicates all transactions were accepted into or are already in the mempool.
+      "tx-results" : {                  (json object) transaction results keyed by wtxid
+        "wtxid" : {                     (json object) transaction wtxid
+          "txid" : "hex",               (string) The transaction hash in hex
+          "other-wtxid" : "hex",        (string, optional) The wtxid of a different transaction with the same txid but different witness found in the mempool. This means the submitted transaction was ignored.
+          "vsize" : n,                  (numeric, optional) Sigops-adjusted virtual transaction size.
+          "fees" : {                    (json object, optional) Transaction fees
+            "base" : n,                 (numeric) transaction fee in BTC
+            "effective-feerate" : n,    (numeric, optional) if the transaction was not already in the mempool, the effective feerate in BTC per KvB. For example, the package feerate and/or feerate with modified fees from prioritisetransaction.
+            "effective-includes" : [    (json array, optional) if effective-feerate is provided, the wtxids of the transactions whose fees and vsizes are included in effective-feerate.
+              "hex",                    (string) transaction wtxid in hex
+              ...
+            ]
+          },
+          "error" : "str"               (string, optional) The transaction error string, if it was rejected by the mempool
+        },
+        ...
+      },
+      "replaced-transactions" : [       (json array, optional) List of txids of replaced transactions
+        "hex",                          (string) The transaction id
+        ...
+      ]
+    }
+
 blockchain.transaction.get
 ==========================
 
@@ -795,6 +889,42 @@ pool, weighted by transaction size.
    [[59.5, 30324], [40.1, 34305], [35.0, 38459], [29.3, 41270], [27.0, 45167], [24.3, 53512], [22.9, 53488], [21.8, 70279], [20.0, 65328], [18.2, 72180], [18.1, 5254], [18.0, 191579], [16.5, 103640], [15.7, 106715], [15.1, 141776], [14.0, 183261], [13.5, 166496], [11.8, 166050], [11.1, 242436], [9.2, 184043], [7.1, 202137], [5.2, 222011], [4.8, 344788], [4.6, 17101], [4.5, 1696864], [4.1, 598001], [4.0, 32688687], [3.9, 505192], [3.8, 38417], [3.7, 2944970], [3.3, 693364], [3.2, 726373], [3.1, 308878], [3.0, 11884957], [2.6, 996967], [2.3, 822802], [2.2, 9075547], [2.1, 12149801], [2.0, 16387874], [1.4, 873120], [1.3, 3493364], [1.1, 2302460], [1.0, 23204633]]
 
 
+mempool.get_info
+================
+
+Returns details on the active state of the TX memory pool.
+
+**Signature**
+
+  .. function:: mempool.get_info()
+
+**Result**
+
+  A dictionary with the following keys:
+
+    * `mempoolminfee`
+        * Type: floating point number
+        * Value:
+            Dynamic minimum fee rate in BTC/kvB for tx to be accepted given current conditions.
+            The maximum of minrelaytxfee and minimum mempool fee, in BTC/kvB.
+    * `minrelaytxfee`
+        * Type: floating point number
+        * Value: Static operator-configurable minimum relay fee for transactions, in BTC/kvB.
+    * `incrementalrelayfee`
+        * Type: floating point number
+        * Value: Static operator-configurable minimum fee rate increment for mempool limiting or replacement, in BTC/kvB.
+
+**Example Result**
+
+::
+
+  {
+      "mempoolminfee": 0.00001000,
+      "minrelaytxfee": 0.00001000,
+      "incrementalrelayfee": 0.00001000
+  }
+
+
 server.add_peer
 ===============
 
@@ -991,11 +1121,14 @@ server.version
 ==============
 
 Identify the client to the server and negotiate the protocol version.
+This must be the first message sent on the wire.
 Only the first :func:`server.version` message is accepted.
 
 **Signature**
 
   .. function:: server.version(client_name="", protocol_version="1.4")
+  .. versionchanged:: 1.6
+     server must tolerate and ignore extraneous args
 
   * *client_name*
 
@@ -1008,6 +1141,9 @@ Only the first :func:`server.version` message is accepted.
     they can be passed as a single string rather than as an array of
     two strings, as for the default value.
 
+  Extraneous unknown args MUST be tolerated and ignored by the server,
+  to allow for future extensions.
+
   The server should use the highest protocol version both support::
 
     version = min(client.protocol_max, server.protocol_max)
@@ -1037,6 +1173,16 @@ Only the first :func:`server.version` message is accepted.
 
   ["ElectrumX 1.2.1", "1.2"]
 
+**Example**
+
+  Redundant unknown arguments MUST be ignored and tolerated by the server::
+
+    server.version("electrum/4.6.2", ["1.4", "1.6"], "trailing_garbage1", 9999.9, "dd": {})
+
+**Example Result**::
+
+  ["ElectrumX 1.18.0", "1.4"]
+
 
 Some more stuff for altcoins
 ============================
diff --git a/docs/protocol-removed.rst b/docs/protocol-removed.rst
index b6b293a..d6d3810 100644
--- a/docs/protocol-removed.rst
+++ b/docs/protocol-removed.rst
@@ -323,6 +323,33 @@ bandwidth-intensive request.
     implied starting height will be returned; this may range from zero
     to the coin-specific chunk size.
 
+
+blockchain.relayfee
+===================
+
+Feerates lower than this are considered zero fee and are not being
+relayed to the bitcoin network by the server.
+This feerate does not guarantee acceptance into the mempool of the server.
+
+**Signature**
+
+  .. function:: blockchain.relayfee()
+
+**Result**
+
+  The feerate in BTC/kvB, as a floating point number.
+
+**Example Results**
+
+::
+
+   1e-05
+
+::
+
+   0.0
+
+
 server.version
 ==============