het volgende geschreven:
>
> Hi All,
>
> I've been working on formalizing the Output Script Descriptors that have
> been available in Bitcoin Core for a while into BIPs. Since descriptors
> are modular and have optional components, I've decided to split it into
> 7 BIPs, rather than a single one. The first describes descriptors in
> general and does not specify any particular descriptor. However it does
> describe the general operation, key expressions (including derivation
> paths and key origin info), and the descriptor checksum. The following 6
> BIPs specify the actual descriptors themselves. These are non-segwit
> descriptor (pk, pkh, sh), segwit descriptors (wpkh, wsh), multisig
> descriptors (multi, sortedmulti), the taproot descriptor (tr), the combo
> descriptor, and opaque descriptors (raw, addr). This separation is so
> that implementors can choose to not implement some descriptors and still
> say which descriptors they support without being too difficult to
> understand.
>
> The text of all of the documents are below, and they can also be found
> on github:https://github.com/achow101/bips/tree/descriptors/
>
> Thanks,
> Andrew Chow
>
> ---
>
>
> BIP: bip-descriptors-general
> Layer: Applications
> Title: Output Script Descriptors General Operation
> Author: Pieter Wuille
> Andrew Chow
> Comments-Summary: No comments yet.
> Comments-URI:
> https://github.com/bitcoin/bips/wiki/Comments:BIP-descriptors-general
> Status: Draft
> Type: Informational
> Created: 2021-06-27
> License: BSD-2-Clause
>
>
> ==Abstract==
>
> Output Script Descriptors are a simple language which can be used to
> describe collections ofoutput scripts.
> There can be many different descriptor fragments and functions.
> This document describes the general syntax for descriptors, descriptor
> checksums, and common expressions.
>
> ==Copyright==
>
> This BIP is licensed under the BSD 2-clause license.
>
> ==Motivation==
>
> Bitcoin wallets traditionally have stored a set of keys which are later
> serialized and mutated to produce the output scripts that the wallet
> watches and the addresses it provides to users.
> Typically backups have consisted of solely the private keys, nowadays
> primarily in the form of BIP 39 mnemonics.
> However this backup solution is insuffient, especially since the
> introduction of Segregated Witness which added new output types.
> Given just the private keys, it is not possible for restored wallets to
> know which kinds of output scripts and addresses to produce.
> This has lead to incompatibilities between wallets when restoring a
> backup or exporting data for a watch only wallet.
>
> Further complicating matters are BIP 32 derivation paths.
> Although BIPs 44, 49, and 84 have specified standard BIP 32 derivation
> paths for different output scripts and addresses, not all wallets
> support them nor use those derivation paths.
> The lack of derivation path information in these backups and exports
> leads to further incompatibilities between wallets.
>
> Current solutions to these issues have not been generic and can be
> viewed as being layer violations.
> Solutions such as introducing different version bytes for extended key
> serialization both are a layer violation (key derivation should be
> separate from script type meaning) and specific only to a particular
> derivation path and script type.
>
> Output Script Descriptors introduces a generic solution to these issues.
> Script types are specified explicitly through the use of Script Expressions.
> Key derivation paths are specified explicitly in Key Expressions.
> These allow for creating wallet backups and exports which specify the
> exact scripts, subscripts (redeemScript, witnessScript, etc.), and keys
> to produce.
> With the general structure specified in this BIP, new Script Expressions
> can be introduced as new script types are added.
> Lastly, the use of common terminology and existing standards allow for
> Output Script Descriptors to be engineer readable so that the results
> can be understood at a glance.
>
> ==Specification==
>
> Descriptors consist of several types of expressions.
> The top level expression is a SCRIPT.
> This expression may be followed by #CHECKSUM, where
> CHECKSUM is an 8 character alphanumeric descriptor checksum.
>
> ===Script Expressions===
>
> Script Expressions (denoted SCRIPT) are expressions which
> correspond directly with a Bitcoin script.
> These expressions are written as functions and take arguments.
> Such expressions have a script template which is filled with the
> arguments correspondingly.
> Expressions are written with a human readable identifier string with the
> arguments enclosed with parentheses.
> The identifier string should be alphanumeric and may include underscores.
>
> The arguments to a script expression are defined by that expression itself.
> They could be a script expression, a key expression, or some other
> expression entirely.
>
> ===Key Expressions===
>
> A common expression used as an argument to script expressions are key
> expressions (denoted KEY).
> These represent a public or private key and, optionally, information
> about the origin of that key.
> Key expressions can only be used as arguments to script expressions.
>
> Key expressions consist of:
> * Optionally, key origin information, consisting of:
> ** An open bracket [
> ** Exactly 8 hex characters for the fingerprint of the key where the
> derivation starts (see BIP 32 for details)
> ** Followed by zero or more /NUM or /NUM' path
> elements to indicate the unhardened or hardened derivation steps between
> the fingerprint and the key that follows.
> ** A closing bracket ]
> * Followed by the actual key, which is either:
> ** A hex encoded public key, which depending the script expression, may
> be either:
> *** 66 hex character string beginning with 02 or 03
> representing a compressed public key
> *** 130 hex character string beginning with 04 representing an
> uncompressed public key
> *** 64 hex character string representing an x-only public key
> ** A [[https://en.bitcoin.it/wiki/Wallet_import_format|WIF]] encoded
> private key
> ** xpub encoded extended public key or xprv encoded
> extended private key (as defined in BIP 32)
> *** Followed by zero or more /NUM or /NUM' path
> elements indicating BIP 32 derivation steps to be taken after the given
> extended key.
> *** Optionally followed by a single /* or /*' final
> step to denote all direct unhardened or hardened children.
>
> If the KEY is a BIP 32 extended key, before output scripts can
> be created, child keys must be derived using the derivation information
> that follows the extended key.
> When the final step is /* or /*', an output script
> will be produced for every child key index.
> The derived key must be serialized as a compressed public key.
>
> In the above specification, the hardened indicator ' may be
> replaced with alternative hardnened indicators of h or H.
>
> ===Character Set===
>
> The expressions used in descriptors must only contain characters within
> this character set so that the descriptor checksum will work.
>
> The allowed characters are:
>
> 0123456789()[],'/*abcdefgh@:$%{}
> IJKLMNOPQRSTUVWXYZ&+-.;<=>?!^_|~
> ijklmnopqrstuvwxyzABCDEFGH`#"\
>
> Note that on the last line is a space character.
>
> This character set is written as 3 groups of 32 characters in this
> specific order so that the checksum below can identify more errors.
> The first group are the most common "unprotected" characters (i.e.
> things such as hex and keypaths that do not already have their own
> checksums).
> Case errors cause an offset that is a multiple of 32 while as many
> alphabetic characters are in the same group while following the previous
> restrictions.
>
> ===Checksum===
>
> Follwing the top level script expression is a single octothorpe
> (#) followed by the 8 character checksum.
> The checksum is an error correcting checksum similar to bech32.
>
> The checksum has the following properties:
> * Mistakes in a descriptor string are measured in "symbol errors". The
> higher the number of symbol errors, the harder it is to detect:
> ** An error substituting a character from
> 0123456789()[],'/*abcdefgh@:$%{} for another in that set always
> counts as 1 symbol error.
> *** Note that hex encoded keys are covered by these characters. Extended
> keys (xpub and xprv) use other characters too, but
> also have their own checksum mechansim.
> *** SCRIPT expression function names use other characters, but
> mistakes in these would generally result in an unparsable descriptor.
> ** A case error always counts as 1 symbol error.
> ** Any other 1 character substitution error counts as 1 or 2 symbol errors.
> * Any 1 symbol error is always detected.
> * Any 2 or 3 symbol error in a descriptor of up to 49154 characters is
> always detected.
> * Any 4 symbol error in a descriptor of up to 507 characters is always
> detected.
> * Any 5 symbol error in a descriptor of up to 77 characters is always
> detected.
> * Is optimized to minimize the chance of a 5 symbol error in a
> descriptor up to 387 characters is undetected
> * Random errors have a chance of 1 in 240 of being
> undetected.
>
> The checksum itself uses the same character set as bech32:
> qpzry9x8gf2tvdw0s3jn54khce6mua7l
>
> Valid descriptor strings with a checksum must pass the criteria for
> validity specified by the Python3 code snippet below.
> The function descsum_check must return true when its argument
> s is a descriptor consisting in the form SCRIPT#CHECKSUM.
>
>
> INPUT_CHARSET =
> "0123456789()[],'/*abcdefgh@:$%{}IJKLMNOPQRSTUVWXYZ&+-.;<=>?!^_|~ijklmnopqrstuvwxyzABCDEFGH`#\"\\
> "
> CHECKSUM_CHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
> GENERATOR = [0xf5dee51989, 0xa9fdca3312, 0x1bab10e32d, 0x3706b1677a,
> 0x644d626ffd]
>
> def descsum_polymod(symbols):
> """Internal function that computes the descriptor checksum."""
> chk = 1
> for value in symbols:
> top = chk >> 35
> chk = (chk & 0x7ffffffff) << 5 ^ value
> for i in range(5):
> chk ^= GENERATOR[i] if ((top >> i) & 1) else 0
> return chk
>
> def descsum_expand(s):
> """Internal function that does the character to symbol expansion"""
> groups = []
> symbols = []
> for c in s:
> if not c in INPUT_CHARSET:
> return None
> v = INPUT_CHARSET.find(c)
> symbols.append(v & 31)
> groups.append(v >> 5)
> if len(groups) == 3:
> symbols.append(groups[0] * 9 + groups[1] * 3 + groups[2])
> groups = []
> if len(groups) == 1:
> symbols.append(groups[0])
> elif len(groups) == 2:
> symbols.append(groups[0] * 3 + groups[1])
> return symbols
>
> def descsum_check(s):
> """Verify that the checksum is correct in a descriptor"""
> if s[-9] != '#':
> return False
> if not all(x in CHECKSUM_CHARSET for x in s[-8:]):
> return False
> symbols = descsum_expand(s[:-9]) + [CHECKSUM_CHARSET.find(x) for x
> in s[-8:]]
> return descsum_polymod(symbols) == 1
>
>
> This implements a BCH code that has the properties described above.
> The entire descriptor string is first processed into an array of symbols.
> The symbol for each character is its position within its group.
> After every 3rd symbol, a 4th symbol is inserted which represents the
> group numbers combined together.
> This means that a change that only affects the position within a group,
> or only a group number change, will only affect a single symbol.
>
> To construct a valid checksum given a script expression, the code below
> can be used:
>
>
> def descsum_create(s):
> """Add a checksum to a descriptor without"""
> symbols = descsum_expand(s) + [0, 0, 0, 0, 0, 0, 0, 0]
> checksum = descsum_polymod(symbols) ^ 1
> return s + '#' + ''.join(CHECKSUM_CHARSET[(checksum >> (5 * (7 -
> i))) & 31] for i in range(8))
>
>
>
> ==Backwards Compatibility==
>
> Output script descriptors are an entirely new language which is not
> compatible with any existing software.
> However many components of the expressions reuse encodings and
> serializations defined by previous BIPs.
>
> Output script descriptors are designed for future extension with further
> fragment types and new script expressions.
> These will be specified in additional BIPs.
>
> ==Reference Implemntation==
>
> Descriptors have been implemented in Bitcoin Core since version 0.17.
>
> ---
>
>
> BIP: bip-descriptors-segwit
> Layer: Applications
> Title: segwit Output Script Descriptors
> Author: Pieter Wuille
> Andrew Chow
> Comments-Summary: No comments yet.
> Comments-URI:
> https://github.com/bitcoin/bips/wiki/Comments:BIP-descriptors-segwit
> Status: Draft
> Type: Informational
> Created: 2021-06-27
> License: BSD-2-Clause
>
>
> ==Abstract==
>
> This document specifies wpkh(), and wsh() output
> script descriptors.
> wpkh() descriptors take a key and produces a P2WPKH output script.
> wsh() descriptors take a script and produces a P2WSH output script.
>
> ==Copyright==
>
> This BIP is licensed under the BSD 2-clause license.
>
> ==Motivation==
>
> Segregated Witness added 2 additional standard output script formats:
> P2WPKH and P2WSH.
> These expressions allow specifying those formats as a descriptor.
>
> ==Specification==
>
> Two new script expressions are defined: wpkh(), and wsh().
>
> ===wpkh()===
>
> The wpkh(KEY) expression can be used as a top level expression,
> or inside of a sh() descriptor.
> It takes a single key expression as an argument and produces a P2WPKH
> output script.
> Only keys which are/has compressed public keys can be contained in a
> wpkh() expression.
>
> The output script produced is:
>
> OP_0
>
>
> ===wsh()===
>
> The wsh(SCRIPT) expression can be used as a top level
> expression, or inside of a sh() descriptor.
> It takes a single script expression as an argument and produces a P2WSH
> output script.
> wsh() expressions also create a witnessScript which is required
> in order to spend outputs which use its output script.
> This redeemScript is the output script produced by the SCRIPT
> argument to wsh().
> Any key expression found in any script expression contained by a
> wsh() expression must only produce compresed public keys.
>
> The output script produced is:
>
> OP_0
>
>
> ==Test Vectors==
>
> TBD
>
> ==Backwards Compatibility==
>
> wpkh(), and wsh() descriptors use the format and
> general operation specified in
> [[bip-descriptor-general.mediawiki|bip-descriptor-general]].
> As these are a wholly new descriptors, they are not compatible with any
> implementation.
> However the scripts produced are standard scripts so existing software
> are likely to be familiar with them.
>
> ==Reference Implemntation==
>
> wpkh(), and wsh() descriptors have been implemented in
> Bitcoin Core since version 0.17.
>
> ---
>
>
> BIP: bip-descriptors-non-segwit
> Layer: Applications
> Title: Non-segwit Output Script Descriptors
> Author: Pieter Wuille
> Andrew Chow
> Comments-Summary: No comments yet.
> Comments-URI:
> https://github.com/bitcoin/bips/wiki/Comments:BIP-descriptors-non-segwit
> Status: Draft
> Type: Informational
> Created: 2021-06-27
> License: BSD-2-Clause
>
>
> ==Abstract==
>
> This document specifies pk(), pkh(), and sh()
> output script descriptors.
> pk() descriptors take a key and produces a P2PK output script.
> pkh() descriptors take a key and produces a P2PKH output script.
> sh() descriptors take a script and produces a P2SH output script.
>
> ==Copyright==
>
> This BIP is licensed under the BSD 2-clause license.
>
> ==Motivation==
>
> Prior to the activation of Segregated Witness, there were 3 main
> standard output script formats: P2PK, P2PKH, and P2SH.
> These expressions allow specifying those formats as a descriptor.
>
> ==Specification==
>
> Three new script expressions are defined: pk(), pkh(),
> and sh().
>
> ===pk()===
>
> The pk(KEY) expression can be used in any context or level of a
> descriptor.
> It takes a single key expression as an argument and produces a P2PK
> output script.
> Depending on the higher level descriptors, there may be restrictions on
> the type of public keys that can be included.
> Such restrictions will be specified by those descriptors.
>
> The output script produced is:
>
> OP_CHECKSIG
>
>
> ===pkh()===
>
> The pkh(KEY) expression can be used as a top level expression,
> or inside of either a sh() or wsh() descriptor.
> It takes a single key expression as an argument and produces a P2PKH
> output script.
> Depending on the higher level descriptors, there may be restrictions on
> the type of public keys that can be included.
> Such restrictions will be specified by those descriptors.
>
> The output script produced is:
>
> OP_DUP OP_HASH160 OP_EQUALVERIFY OP_CHECKSIG
>
>
> ===sh()===
>
> The sh(SCRIPT) expression can only be used as a top level
> expression.
> It takes a single script expression as an argument and produces a P2SH
> output script.
> sh() expressions also create a redeemScript which is required
> in order to spend outputs which use its output script.
> This redeemScript is the output script produced by the SCRIPT
> argument to sh().
>
> The output script produced is:
>
> OP_HASH160 OP_EQUAL
>
>
> ==Test Vectors==
>
> TBD
>
> ==Backwards Compatibility==
>
> pk(), pkh(), and sh() descriptors use the
> format and general operation specified in
> [[bip-descriptor-general.mediawiki|bip-descriptor-general]].
> As these are a wholly new descriptors, they are not compatible with any
> implementation.
> However the scripts produced are standard scripts so existing software
> are likely to be familiar with them.
>
> ==Reference Implemntation==
>
> pk(), pkh(), and sh() descriptors have been
> implemented in Bitcoin Core since version 0.17.
>
> ---
>
>
> BIP: bip-descriptors-tr
> Layer: Applications
> Title: tr() Output Script Descriptors
> Author: Pieter Wuille
> Andrew Chow
> Comments-Summary: No comments yet.
> Comments-URI:
> https://github.com/bitcoin/bips/wiki/Comments:BIP-descriptors-tr
> Status: Draft
> Type: Informational
> Created: 2021-06-27
> License: BSD-2-Clause
>
>
> ==Abstract==
>
> This document specifies tr() output script descriptors.
> tr() descriptors take a key and optionally a tree of scripts
> and produces a P2TR output script.
>
> ==Copyright==
>
> This BIP is licensed under the BSD 2-clause license.
>
> ==Motivation==
>
> Taproot added one additional standard output script format: P2TR.
> These expressions allow specifying those formats as a descriptor.
>
> ==Specification==
>
> A new script expressions are defined: tr().
> A new expression is defined: Tree Expressions
>
> ===Tree Expression===
>
> A Tree Expression (denoted TREE) is an expression which
> represents a tree of scripts.
> The way the tree is represented in an output script is dependent on the
> higher level expressions.
>
> A Tree Expression is:
> * Any Script Expression that is allowed at the level this Tree
> Expression is in.
> * A pair of Tree Expressions consisting of:
> ** An open brace {
> ** A Tree Expression
> ** A comma ,
> ** A Tree Expression
> ** A closing brance }
>
> ===tr()===
>
> The tr(KEY) or tr(KEY, TREE) expression can only be
> used as a top level expression.
> All key expressions under any tr() expression must create
> x-only public keys.
>
> tr(KEY takes a single key expression as an argument and
> produces a P2TR output script which does not have a script path.
> The keys produced by the key expression are used as the internal key as
> specified by [[bip-0341.mediawiki#cite_ref-22-0|BIP 341]].
> Specifically, "If the spending conditions do not require a script path,
> the output key should commit to an unspendable script path instead of
> having no script path.
> This can be achieved by computing the output key point as ''Q = P +
> int(hashTapTweak(bytes(P)))G''."
>
>
> internal_key: lift_x(KEY)
> 32_byte_output_key: internal_key + int(HashTapTweak(bytes(internal_key)))G
> scriptPubKey: OP_1 <32_byte_output_key>
>
>
> tr(KEY, TREE) takes a key expression as the first argument, and
> a tree expression as the second argument and produces a P2TR output
> script which has a script path.
> The keys produced by the first key expression are used as the internal
> key as specified by
> [[bip-0341.mediawiki#Constructing_and_spending_Taproot_outputs|BIP 341]].
> The Tree expression becomes the Taproot script tree as described in BIP 341.
> A merkle root is computed from this tree and combined with the internal
> key to create the Taproot output key.
>
>
> internal_key: lift_x(KEY)
> merkle_root: HashTapBranch(TREE)
> 32_byte_output_key: internal_key + int(HashTapTweak(bytes(internal_key)
> || merkle_root))G
> scriptPubKey: OP_1 <32_byte_output_key>
>
>
> ==Test Vectors==
>
> TBD
>
> ==Backwards Compatibility==
>
> tr() descriptors use the format and general operation specified
> in [[bip-descriptor-general.mediawiki|bip-descriptor-general]].
> As these are a wholly new descriptors, they are not compatible with any
> implementation.
> However the scripts produced are standard scripts so existing software
> are likely to be familiar with them.
>
> Tree Expressions are largely incompatible with existing script
> expressions due to the restrictions in those expressions.
> As of 2021-06-27, the only allowed script expression that can be used in
> a tree expression is pk().
> However there will be future BIPs that specify script expressions that
> can be used in tree expressions.
>
> ==Reference Implemntation==
>
> tr() descriptors have been implemented in Bitcoin Core since
> version 22.0.
>
> ---
>
>
> BIP: bip-descriptors-multi
> Layer: Applications
> Title: Multisig Output Script Descriptors
> Author: Pieter Wuille
> Andrew Chow
> Comments-Summary: No comments yet.
> Comments-URI:
> https://github.com/bitcoin/bips/wiki/Comments:BIP-descriptors-multi
> Status: Draft
> Type: Informational
> Created: 2021-06-27
> License: BSD-2-Clause
>
>
> ==Abstract==
>
> This document specifies multi(), and sortedmulti()
> output script descriptors.
> Both functions take a threshold and one or more public keys and produce
> a multisig output script.
> multi() specifies the public keys in the output script in the
> order given in the descriptor while sortedmulti() sorts the
> public keys lexicographically when the output script is produced.
>
> ==Copyright==
>
> This BIP is licensed under the BSD 2-clause license.
>
> ==Motivation==
>
> The most common complex script used in Bitcoin is a threshold multisig.
> These expressions allow specifying multisig scripts as a descriptor.
>
> ==Specification==
>
> Two new script expressions are defined: multi(), and
> sortedmulti().
> Both expressions produce the scripts of the same template and take the
> same arguments.
> They are written as multi(k,KEY_1,KEY_2,...,KEY_n).
> k is the threshold - the number of keys that must sign the
> input for the script to be valid.
> KEY_1,KEY_2,...,KEY_n are the key expressions for the multisig.
> k must be less than or equal to n.
>
> multi() and sortedmulti() expressions can be used as a
> top level expression, or inside of either a sh() or
> wsh() descriptor.
> Depending on the higher level descriptors, there may be restrictions on
> the type of public keys that can be included.
>
> Depending on the higher level descriptors, there are also restrictions
> on the number of keys that can be present, i.e. the maximum value of
> n.
> When used at the top level, there can only be at most 3 keys.
> When used inside of a sh() expression, there can only be most
> 15 compressed public keys (this is limited by the P2SH script limit).
> Otherwise the maximum number of keys is 20.
>
> The output script produced also depends on the value of k. If
> k is less than or equal to 16:
>
> OP_k KEY_1 KEY_2 ... KEY_n OP_CHECKMULTISIG
>
>
> if k is greater than 16:
>
> k KEY_1 KEY_2 ... KEY_n OP_CHECKMULTISIG
>
>
> ===sortedmulti()===
>
> The only change for sortedmulti() is that the keys are sorted
> lexicographically prior to the creation of the output script.
> This sorting is on the keys that are to be put into the output script,
> i.e. after all extended keys are derived.
>
> ===Multiple Extended Keys===
>
> When one or more the key expressions in a multi() or
> sortedmulti() expression are extended keys, the derived keys
> use the same child index.
> This changes the keys in lockstep and allows for output scripts to be
> indexed in the same way that the derived keys are indexed.
>
> ==Test Vectors==
>
> TBD
>
> ==Backwards Compatibility==
>
> multi(), and sortedmulti() descriptors use the format
> and general operation specified in
> [[bip-descriptor-general.mediawiki|bip-descriptor-general]].
> As these are a wholly new descriptors, they are not compatible with any
> implementation.
> However the scripts produced are standard scripts so existing software
> are likely to be familiar with them.
>
> ==Reference Implemntation==
>
> multi(), and multi() descriptors have been implemented
> in Bitcoin Core since version 0.17.
>
> ---
>
>
> BIP: bip-descriptors-combo
> Layer: Applications
> Title: combo() Output Script Descriptors
> Author: Pieter Wuille
> Andrew Chow
> Comments-Summary: No comments yet.
> Comments-URI:
> https://github.com/bitcoin/bips/wiki/Comments:BIP-descriptors-combo
> Status: Draft
> Type: Informational
> Created: 2021-06-27
> License: BSD-2-Clause
>
>
> ==Abstract==
>
> This document specifies combo() output script descriptors.
> These take a key and produce P2PK, P2PKH, P2WPKH, and P2SH-P2WPKH output
> scripts if applicable to the key.
>
> ==Copyright==
>
> This BIP is licensed under the BSD 2-clause license.
>
> ==Motivation==
>
> In order to make the transition from traditional key based wallets to
> descriptor based wallets easier, it is useful to be able to take a key
> and produce the scripts which have traditionally been produced by wallet
> software.
>
> ==Specification==
>
> A new top level script expression is defined: combo(KEY).
> This expression can only be used as a top level expression.
> It takes a single key expression as an argument and produces either 2 or
> 4 output scripts, depending on the key.
> A combo() expression always produces a P2PK and P2PKH script,
> the same as putting the key in both a pk() and a pkh()
> expression.
> If the key is/has a compressed public key, then P2WPKH and P2SH-P2WPKH
> scripts are also produced, the same as putting the key in both a
> wpkh() and sh(wpkh()) expression.
>
> ==Test Vectors==
>
> TBD
>
> ==Backwards Compatibility==
>
> combo() descriptors use the format and general operation
> specified in [[bip-descriptor-general.mediawiki|bip-descriptor-general]].
> As this is a wholly new descriptor, it is not compatible with any
> implementation.
> However the scripts produced are standard scripts so existing software
> are likely to be familiar with them.
>
> ==Reference Implemntation==
>
> combo descriptors have been implemented in Bitcoin Core since
> version 0.17.
>
> ---
>
>
> BIP: bip-descriptors-encap
> Layer: Applications
> Title: raw() and addr() Output Script Descriptors
> Author: Andrew Chow
> Pieter Wuille
> Comments-Summary: No comments yet.
> Comments-URI:
> https://github.com/bitcoin/bips/wiki/Comments:BIP-descriptors-raw
> Status: Draft
> Type: Informational
> Created: 2021-06-27
> License: BSD-2-Clause
>
>
> ==Abstract==
>
> This document specifies raw() and addr() output script
> descriptors.
> raw() encapsulates a raw script as a descriptor.
> addr() encapsulates an address as a descriptor.
>
> ==Copyright==
>
> This BIP is licensed under the BSD 2-clause license.
>
> ==Motivation==
>
> In order to make descriptors maximally compatible with scripts in use
> today, it is useful to be able to wrap any arbitrary output script or an
> address into a descriptor.
>
> ==Specification==
>
> Two new script expressions are defined: raw() and addr().
>
> ===raw()===
>
> The raw(HEX) expression can only be used as a top level descriptor.
> As the argument, it takes a hex string representing a Bitcoin script.
> The output script produced by this descriptor is the script represented
> by HEX.
>
> ===addr()===
>
> The addr(ADDR) expression can only be used as a top level
> descriptor.
> It takes an address as its single argument.
> The output script produced by this descriptor is the output script
> produced by the address ADDR.
>
> ==Test Vectors==
>
> TBD
>
> ==Backwards Compatibility==
>
> raw() and addr() descriptors use the format and
> general operation specified in
> [[bip-descriptor-general.mediawiki|bip-descriptor-general]].
> As this is a wholly new descriptor, it is not compatible with any
> implementation.
> The reuse of existing Bitcoin addresses allows for this to be more
> easily implemented.
>
> ==Reference Implemntation==
>
> raw() and addr descriptors have been implemented in
> Bitcoin Core since version 0.17.
>
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