diff --git a/Sources/FoundationEssentials/String/CMakeLists.txt b/Sources/FoundationEssentials/String/CMakeLists.txt
index 720eb218d..6cc7994d7 100644
--- a/Sources/FoundationEssentials/String/CMakeLists.txt
+++ b/Sources/FoundationEssentials/String/CMakeLists.txt
@@ -15,10 +15,12 @@
 target_sources(FoundationEssentials PRIVATE
     BidirectionalCollection.swift
     BuiltInUnicodeScalarSet.swift
+    IANACharsetNames.swift
     RegexPatternCache.swift
     String+Bridging.swift
     String+Comparison.swift
     String+Encoding.swift
+    String+Encoding+Names.swift
     String+EndianAdaptorSequence.swift
     String+Essentials.swift
     String+IO.swift
diff --git a/Sources/FoundationEssentials/String/IANACharsetNames.swift b/Sources/FoundationEssentials/String/IANACharsetNames.swift
new file mode 100644
index 000000000..8f3e88f09
--- /dev/null
+++ b/Sources/FoundationEssentials/String/IANACharsetNames.swift
@@ -0,0 +1,213 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2025 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+
+// WARNING: DO NOT EDIT THIS FILE DIRECTLY.
+//          This is auto-generated by `update-iana-charset-names`.
+
+
+extension IANACharset {
+    /// IANA Charset `US-ASCII`.
+    static let usASCII = IANACharset(
+        preferredMIMEName: "US-ASCII",
+        name: "US-ASCII",
+        aliases: [
+            "iso-ir-6",
+            "ANSI_X3.4-1968",
+            "ANSI_X3.4-1986",
+            "ISO_646.irv:1991",
+            "ISO646-US",
+            "US-ASCII",
+            "us",
+            "IBM367",
+            "cp367",
+            "csASCII",
+        ]
+    )
+
+    /// IANA Charset `ISO-8859-1`.
+    static let iso8859_1 = IANACharset(
+        preferredMIMEName: "ISO-8859-1",
+        name: "ISO_8859-1:1987",
+        aliases: [
+            "iso-ir-100",
+            "ISO_8859-1",
+            "ISO-8859-1",
+            "latin1",
+            "l1",
+            "IBM819",
+            "CP819",
+            "csISOLatin1",
+        ]
+    )
+
+    /// IANA Charset `ISO-8859-2`.
+    static let iso8859_2 = IANACharset(
+        preferredMIMEName: "ISO-8859-2",
+        name: "ISO_8859-2:1987",
+        aliases: [
+            "iso-ir-101",
+            "ISO_8859-2",
+            "ISO-8859-2",
+            "latin2",
+            "l2",
+            "csISOLatin2",
+        ]
+    )
+
+    /// IANA Charset `Shift_JIS`.
+    static let shiftJIS = IANACharset(
+        preferredMIMEName: "Shift_JIS",
+        name: "Shift_JIS",
+        aliases: [
+            "MS_Kanji",
+            "csShiftJIS",
+        ]
+    )
+
+    /// IANA Charset `EUC-JP`.
+    static let eucJP = IANACharset(
+        preferredMIMEName: "EUC-JP",
+        name: "Extended_UNIX_Code_Packed_Format_for_Japanese",
+        aliases: [
+            "csEUCPkdFmtJapanese",
+            "EUC-JP",
+        ]
+    )
+
+    /// IANA Charset `ISO-2022-JP`.
+    static let iso2022JP = IANACharset(
+        preferredMIMEName: "ISO-2022-JP",
+        name: "ISO-2022-JP",
+        aliases: [
+            "csISO2022JP",
+        ]
+    )
+
+    /// IANA Charset `UTF-8`.
+    static let utf8 = IANACharset(
+        preferredMIMEName: nil,
+        name: "UTF-8",
+        aliases: [
+            "csUTF8",
+        ]
+    )
+
+    /// IANA Charset `UTF-16BE`.
+    static let utf16BE = IANACharset(
+        preferredMIMEName: nil,
+        name: "UTF-16BE",
+        aliases: [
+            "csUTF16BE",
+        ]
+    )
+
+    /// IANA Charset `UTF-16LE`.
+    static let utf16LE = IANACharset(
+        preferredMIMEName: nil,
+        name: "UTF-16LE",
+        aliases: [
+            "csUTF16LE",
+        ]
+    )
+
+    /// IANA Charset `UTF-16`.
+    static let utf16 = IANACharset(
+        preferredMIMEName: nil,
+        name: "UTF-16",
+        aliases: [
+            "csUTF16",
+        ]
+    )
+
+    /// IANA Charset `UTF-32`.
+    static let utf32 = IANACharset(
+        preferredMIMEName: nil,
+        name: "UTF-32",
+        aliases: [
+            "csUTF32",
+        ]
+    )
+
+    /// IANA Charset `UTF-32BE`.
+    static let utf32BE = IANACharset(
+        preferredMIMEName: nil,
+        name: "UTF-32BE",
+        aliases: [
+            "csUTF32BE",
+        ]
+    )
+
+    /// IANA Charset `UTF-32LE`.
+    static let utf32LE = IANACharset(
+        preferredMIMEName: nil,
+        name: "UTF-32LE",
+        aliases: [
+            "csUTF32LE",
+        ]
+    )
+
+    /// IANA Charset `macintosh`.
+    static let macintosh = IANACharset(
+        preferredMIMEName: nil,
+        name: "macintosh",
+        aliases: [
+            "mac",
+            "csMacintosh",
+        ]
+    )
+
+    /// IANA Charset `windows-1250`.
+    static let windows1250 = IANACharset(
+        preferredMIMEName: nil,
+        name: "windows-1250",
+        aliases: [
+            "cswindows1250",
+        ]
+    )
+
+    /// IANA Charset `windows-1251`.
+    static let windows1251 = IANACharset(
+        preferredMIMEName: nil,
+        name: "windows-1251",
+        aliases: [
+            "cswindows1251",
+        ]
+    )
+
+    /// IANA Charset `windows-1252`.
+    static let windows1252 = IANACharset(
+        preferredMIMEName: nil,
+        name: "windows-1252",
+        aliases: [
+            "cswindows1252",
+        ]
+    )
+
+    /// IANA Charset `windows-1253`.
+    static let windows1253 = IANACharset(
+        preferredMIMEName: nil,
+        name: "windows-1253",
+        aliases: [
+            "cswindows1253",
+        ]
+    )
+
+    /// IANA Charset `windows-1254`.
+    static let windows1254 = IANACharset(
+        preferredMIMEName: nil,
+        name: "windows-1254",
+        aliases: [
+            "cswindows1254",
+        ]
+    )
+}
diff --git a/Sources/FoundationEssentials/String/String+Encoding+Names.swift b/Sources/FoundationEssentials/String/String+Encoding+Names.swift
new file mode 100644
index 000000000..1407e5ae1
--- /dev/null
+++ b/Sources/FoundationEssentials/String/String+Encoding+Names.swift
@@ -0,0 +1,155 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2025 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+
+// MARK: - Private extensions for parsing encoding names
+
+private extension UTF8.CodeUnit {
+    func _isASCIICaseInsensitivelyEqual(to other: UTF8.CodeUnit) -> Bool {
+        return switch self {
+        case other, other._uppercased, other._lowercased: true
+        default: false
+        }
+    }
+}
+
+private extension String {
+    func _isASCIICaseInsensitivelyEqual(to other: String) -> Bool {
+        let (myUTF8, otherUTF8) = (self.utf8, other.utf8)
+        var (myIndex, otherIndex) = (myUTF8.startIndex, otherUTF8.startIndex)
+        while myIndex < myUTF8.endIndex && otherIndex < otherUTF8.endIndex {
+            guard myUTF8[myIndex]._isASCIICaseInsensitivelyEqual(to: otherUTF8[otherIndex]) else {
+                return false
+            }
+
+            myUTF8.formIndex(after: &myIndex)
+            otherUTF8.formIndex(after: &otherIndex)
+        }
+        return myIndex == myUTF8.endIndex && otherIndex == otherUTF8.endIndex
+    }
+}
+
+
+// MARK: - IANA Charset Names
+
+/// Info about IANA Charset.
+internal struct IANACharset {
+    /// Preferred MIME Name
+    let preferredMIMEName: String?
+
+    /// The name of this charset
+    let name: String
+
+    /// The aliases of this charset
+    let aliases: Array<String>
+
+    var representativeName: String {
+        return preferredMIMEName ?? name
+    }
+
+    init(preferredMIMEName: String?, name: String, aliases: Array<String>) {
+        self.preferredMIMEName = preferredMIMEName
+        self.name = name
+        self.aliases = aliases
+    }
+
+    func matches(_ string: String) -> Bool {
+        if let preferredMIMEName = self.preferredMIMEName,
+           preferredMIMEName._isASCIICaseInsensitivelyEqual(to: string) {
+            return true
+        }
+        if name._isASCIICaseInsensitivelyEqual(to: string) {
+            return true
+        }
+        for alias in aliases {
+            if alias._isASCIICaseInsensitivelyEqual(to: string) {
+                return true
+            }
+        }
+        return false
+    }
+}
+
+
+// MARK: - `String.Encoding` Names
+
+extension String.Encoding {
+    private var _ianaCharset: IANACharset? {
+        switch self {
+        case .utf8: .utf8
+        case .ascii: .usASCII
+        case .japaneseEUC: .eucJP
+        case .isoLatin1: .iso8859_1
+        case .shiftJIS: .shiftJIS
+        case .isoLatin2: .iso8859_2
+        case .unicode: .utf16
+        case .windowsCP1251: .windows1251
+        case .windowsCP1252: .windows1252
+        case .windowsCP1253: .windows1253
+        case .windowsCP1254: .windows1254
+        case .windowsCP1250: .windows1250
+        case .iso2022JP: .iso2022JP
+        case .macOSRoman: .macintosh
+        case .utf16BigEndian: .utf16BE
+        case .utf16LittleEndian: .utf16LE
+        case .utf32: .utf32
+        case .utf32BigEndian: .utf32BE
+        case .utf32LittleEndian: .utf32LE
+        default: nil
+        }
+    }
+
+    /// The name of this encoding that is compatible with the one of the IANA registry "charset".
+    @available(FoundationPreview 6.3, *)
+    public var ianaName: String? {
+        return _ianaCharset?.representativeName
+    }
+
+    /// Creates an instance from the name of the IANA registry "charset".
+    ///
+    /// - Note: The given name is compared to each IANA "charset" name
+    ///         with ASCII case-insensitive collation
+    ///         to determine which encoding is suitable.
+    @available(FoundationPreview 6.3, *)
+    public init?(ianaName charsetName: String) {
+        let possibilities: [String.Encoding] = [
+            .utf8,
+            .ascii,
+            .japaneseEUC,
+            .isoLatin1,
+            .shiftJIS,
+            .isoLatin2,
+            .unicode, // .utf16
+            .windowsCP1251,
+            .windowsCP1252,
+            .windowsCP1253,
+            .windowsCP1254,
+            .windowsCP1250,
+            .iso2022JP,
+            .macOSRoman,
+            .utf16BigEndian,
+            .utf16LittleEndian,
+            .utf32,
+            .utf32BigEndian,
+            .utf32LittleEndian,
+        ]
+
+        for encoding in possibilities {
+            if encoding._ianaCharset!.matches(charsetName) {
+                self = encoding
+                return
+            }
+        }
+        return nil
+    }
+}
+
diff --git a/Tests/FoundationEssentialsTests/StringTests.swift b/Tests/FoundationEssentialsTests/StringTests.swift
index 26286be15..6a6781874 100644
--- a/Tests/FoundationEssentialsTests/StringTests.swift
+++ b/Tests/FoundationEssentialsTests/StringTests.swift
@@ -1397,6 +1397,69 @@ private struct StringTests {
             "abcd🎺efgh"
         ])
     }
+
+    @Test func encodingNames() {
+        // Encoding to Name
+        #expect(String.Encoding.ascii.ianaName == "US-ASCII")
+        #expect(String.Encoding.nextstep.ianaName == nil)
+        #expect(String.Encoding.japaneseEUC.ianaName == "EUC-JP")
+        #expect(String.Encoding.utf8.ianaName == "UTF-8")
+        #expect(String.Encoding.isoLatin1.ianaName == "ISO-8859-1")
+        #expect(String.Encoding.symbol.ianaName == nil)
+        #expect(String.Encoding.nonLossyASCII.ianaName == nil)
+        #expect(String.Encoding.shiftJIS.ianaName == "Shift_JIS")
+        #expect(String.Encoding.isoLatin2.ianaName == "ISO-8859-2")
+        #expect(String.Encoding.unicode.ianaName == "UTF-16")
+        #expect(String.Encoding.windowsCP1251.ianaName == "windows-1251")
+        #expect(String.Encoding.windowsCP1252.ianaName == "windows-1252")
+        #expect(String.Encoding.windowsCP1253.ianaName == "windows-1253")
+        #expect(String.Encoding.windowsCP1254.ianaName == "windows-1254")
+        #expect(String.Encoding.windowsCP1250.ianaName == "windows-1250")
+        #expect(String.Encoding.iso2022JP.ianaName == "ISO-2022-JP")
+        #expect(String.Encoding.macOSRoman.ianaName == "macintosh")
+        #expect(String.Encoding.utf16BigEndian.ianaName == "UTF-16BE")
+        #expect(String.Encoding.utf16LittleEndian.ianaName == "UTF-16LE")
+        #expect(String.Encoding.utf32.ianaName == "UTF-32")
+        #expect(String.Encoding.utf32BigEndian.ianaName == "UTF-32BE")
+        #expect(String.Encoding.utf32LittleEndian.ianaName == "UTF-32LE")
+        #expect(String.Encoding(rawValue: .max).ianaName == nil)
+
+        // Name to Encoding
+        #expect(String.Encoding(ianaName: "us-ascii") == .ascii)
+        #expect(String.Encoding(ianaName: "iso-ir-2") == nil)
+        #expect(String.Encoding(ianaName: "x-nextstep") == nil)
+        #expect(String.Encoding(ianaName: "euc-jp") == .japaneseEUC)
+        #expect(String.Encoding(ianaName: "CP51932") == nil)
+        #expect(String.Encoding(ianaName: "utf-8") == .utf8)
+        #expect(String.Encoding(ianaName: "iso_8859-1") == .isoLatin1)
+        #expect(String.Encoding(ianaName: "x-mac-symbol") == nil)
+        #expect(String.Encoding(ianaName: "Adobe-symbol-encoding") == nil)
+        #expect(String.Encoding(ianaName: "cp932") == nil)
+        #expect(String.Encoding(ianaName: "shift_jis") == .shiftJIS)
+        #expect(String.Encoding(ianaName: "windows-31j") == nil)
+        #expect(String.Encoding(ianaName: "iso_8859-2") == .isoLatin2)
+        #expect(String.Encoding(ianaName: "utf-16") == .utf16)
+        #expect(String.Encoding(ianaName: "iso-10646-ucs-2") == nil)
+        #expect(String.Encoding(ianaName: "unicode-1-1") == nil)
+        #expect(String.Encoding(ianaName: "windows-1251") == .windowsCP1251)
+        #expect(String.Encoding(ianaName: "windows-1252") == .windowsCP1252)
+        #expect(String.Encoding(ianaName: "ISO-8859-1-Windows-3.0-Latin-1") == nil)
+        #expect(String.Encoding(ianaName: "ISO-8859-1-Windows-3.1-Latin-1") == nil)
+        #expect(String.Encoding(ianaName: "windows-1253") == .windowsCP1253)
+        #expect(String.Encoding(ianaName: "windows-1254") == .windowsCP1254)
+        #expect(String.Encoding(ianaName: "iso-8859-9-windows-Latin-5") == nil)
+        #expect(String.Encoding(ianaName: "windows-1250") == .windowsCP1250)
+        #expect(String.Encoding(ianaName: "iso-8859-2-windows-Latin-2") == nil)
+        #expect(String.Encoding(ianaName: "iso-2022-jp") == .iso2022JP)
+        #expect(String.Encoding(ianaName: "macintosh") == .macOSRoman)
+        #expect(String.Encoding(ianaName: "utf-16be") == .utf16BigEndian)
+        #expect(String.Encoding(ianaName: "utf-16le") == .utf16LittleEndian)
+        #expect(String.Encoding(ianaName: "utf-32") == .utf32)
+        #expect(String.Encoding(ianaName: "iso-10646-ucs-4") == nil)
+        #expect(String.Encoding(ianaName: "utf-32be") == .utf32BigEndian)
+        #expect(String.Encoding(ianaName: "utf-32le") == .utf32LittleEndian)
+        #expect(String.Encoding(ianaName: "foo-bar-baz") == nil)
+    }
 }
 
 // MARK: - Helper functions
diff --git a/utils/update-iana-charset-names b/utils/update-iana-charset-names
new file mode 100755
index 000000000..e56e972b1
--- /dev/null
+++ b/utils/update-iana-charset-names
@@ -0,0 +1,62 @@
+#!/usr/bin/env bash
+##===----------------------------------------------------------------------===##
+##
+## This source file is part of the Swift.org open source project
+##
+## Copyright (c) 2025 Apple Inc. and the Swift project authors
+## Licensed under Apache License v2.0 with Runtime Library Exception
+##
+## See https://swift.org/LICENSE.txt for license information
+## See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+##
+##===----------------------------------------------------------------------===##
+
+# This is a shell script that generates a Swift source code file which contains
+# the list of IANA "Character Sets".
+
+set -eu
+
+declare -r commandName="$(basename "$0")"
+declare -r utilsDir="$(cd "$(dirname "$0")" && pwd)"
+declare -r foundationRepoDir="$(cd "${utilsDir}/.." && pwd)"
+declare -r targetSwiftFileRelativePath="Sources/FoundationEssentials/String/IANACharsetNames.swift"
+
+declare -r copyrightYear=$(
+  currentYear=$(date +%Y)
+  if [[ $currentYear -eq 2025 ]]; then
+    echo 2025
+  else
+    echo 2025-${currentYear}
+  fi
+)
+declare -r swiftLicenseHeader="
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) ${copyrightYear} Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+"
+declare -r warningComment="
+// WARNING: DO NOT EDIT THIS FILE DIRECTLY.
+//          This is auto-generated by \`${commandName}\`.
+
+"
+
+echo "Generating Swift source code..." 1>&2
+declare generatedCode
+generatedCode=$(
+  echo "${swiftLicenseHeader##$'\n'}"
+  echo "$warningComment"
+  swift -D PRINT_CODE "${utilsDir}/${commandName}-impl.swift"
+)
+
+echo "Writing the code to '${targetSwiftFileRelativePath}'..." 1>&2
+echo "$generatedCode" >"${foundationRepoDir}/${targetSwiftFileRelativePath}"
+
+echo "Done." 1>&2
diff --git a/utils/update-iana-charset-names-impl.swift b/utils/update-iana-charset-names-impl.swift
new file mode 100755
index 000000000..c7e83e0d8
--- /dev/null
+++ b/utils/update-iana-charset-names-impl.swift
@@ -0,0 +1,195 @@
+#!/usr/bin/env swift -D PRINT_CODE
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2025 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+
+/*
+
+This is a Swift script that converts an XML file containing the list of IANA
+"Character Sets" to Swift source code.
+This script generates minimum code and is intended to be executed by other shell
+script.
+
+ */
+
+import Foundation
+#if canImport(FoundationXML)
+import FoundationXML
+#endif
+
+// MARK: - Constants
+
+let requiredCharsetNames = [
+    "UTF-8",
+    "US-ASCII",
+    "EUC-JP",
+    "ISO-8859-1",
+    "Shift_JIS",
+    "ISO-8859-2",
+    "UTF-16",
+    "windows-1251",
+    "windows-1252",
+    "windows-1253",
+    "windows-1254",
+    "windows-1250",
+    "ISO-2022-JP",
+    "macintosh",
+    "UTF-16BE",
+    "UTF-16LE",
+    "UTF-32",
+    "UTF-32BE",
+    "UTF-32LE",
+]
+let charsetsXMLURL = URL(
+    string: "https://www.iana.org/assignments/character-sets/character-sets.xml"
+)!
+let charsetsXMLNamespace = "http://www.iana.org/assignments"
+let swiftCodeIndent = "    "
+
+
+// MARK: - Implementation
+
+enum CodeGenerationError: Swift.Error {
+    case missingName
+    case missingAliasValue
+    case noRootElement
+}
+
+/// Representation of <record> element in 'character-sets.xml'
+///
+/// The structure of <record> element is as blow:
+/// ```xml
+/// <record>
+///     <name>US-ASCII</name>
+///     <xref type="rfc" data="rfc2046"/>
+///     <value>3</value>
+///     <description>ANSI X3.4-1986</description>
+///     <alias>iso-ir-6</alias>
+///     <alias>ANSI_X3.4-1968</alias>
+///     <alias>ANSI_X3.4-1986</alias>
+///     <alias>ISO_646.irv:1991</alias>
+///     <alias>ISO646-US</alias>
+///     <alias>US-ASCII</alias>
+///     <alias>us</alias>
+///     <alias>IBM367</alias>
+///     <alias>cp367</alias>
+///     <alias>csASCII</alias>
+///     <preferred_alias>US-ASCII</preferred_alias>
+/// </record>
+/// ```
+struct IANACharsetNameRecord {
+    /// Preferred MIME Name
+    let preferredMIMEName: String?
+
+    /// The name of this charset
+    let name: String
+
+    /// The aliases of this charset
+    let aliases: Array<String>
+
+    var representativeName: String {
+        return preferredMIMEName ?? name
+    }
+
+    var swiftCodeLines: [String] {
+        var lines: [String] = []
+        lines.append("/// IANA Charset `\(representativeName)`.")
+        lines.append("static let \(representativeName._camelcased()) = IANACharset(")
+        lines.append("\(swiftCodeIndent)preferredMIMEName: \(preferredMIMEName.map { #""\#($0)""# } ?? "nil"),")
+        lines.append("\(swiftCodeIndent)name: \"\(name)\",")
+        lines.append("\(swiftCodeIndent)aliases: [")
+        for alias in aliases {
+            lines.append("\(swiftCodeIndent)\(swiftCodeIndent)\"\(alias)\",")
+        }
+        lines.append("\(swiftCodeIndent)]")
+        lines.append(")")
+        return lines
+    }
+
+    init(_ node: XMLNode) throws {
+        guard let name = try node.nodes(forXPath: "./name").first?.stringValue else {
+            throw CodeGenerationError.missingName
+        }
+        self.name = name
+        self.preferredMIMEName = try node.nodes(forXPath: "./preferred_alias").first?.stringValue
+        self.aliases = try node.nodes(forXPath: "./alias").map {
+            guard let alias = $0.stringValue else {
+                throw CodeGenerationError.missingAliasValue
+            }
+            return alias
+        }
+    }
+}
+
+func generateSwiftCode() throws -> String {
+    let charsetsXMLDocument = try XMLDocument(contentsOf: charsetsXMLURL)
+    guard let charsetsXMLRoot = charsetsXMLDocument.rootElement() else {
+        throw CodeGenerationError.noRootElement
+    }
+    let charsetsXMLRecordElements = try charsetsXMLRoot.nodes(forXPath: "./registry/record")
+
+    var result = "extension IANACharset {"
+
+    for record in try charsetsXMLRecordElements.map({
+        try IANACharsetNameRecord($0)
+    }) where requiredCharsetNames.contains(record.representativeName) {
+        result += "\n"
+        result += record.swiftCodeLines.map({ swiftCodeIndent + $0 }).joined(separator: "\n")
+        result += "\n"
+    }
+
+    result += "}\n"
+    return result
+}
+
+#if PRINT_CODE
+print(try generateSwiftCode())
+#endif
+
+// MARK: - Extensions
+
+extension UTF8.CodeUnit {
+    var _isASCIINumeric: Bool { (0x30...0x39).contains(self) }
+    var _isASCIIUppercase: Bool { (0x41...0x5A).contains(self) }
+    var _isASCIILowercase: Bool { (0x61...0x7A).contains(self) }
+}
+
+extension String {
+    func _camelcased() -> String {
+        var result = ""
+        var previousWord: Substring.UTF8View? = nil
+        for wordUTF8 in self.utf8.split(whereSeparator: {
+            !$0._isASCIINumeric &&
+            !$0._isASCIIUppercase &&
+            !$0._isASCIILowercase
+        }) {
+            defer {
+                previousWord = wordUTF8
+            }
+            let word = String(Substring(wordUTF8))
+            guard let previousWord else {
+                result += word.lowercased()
+                continue
+            }
+            if previousWord.last!._isASCIINumeric && wordUTF8.first!._isASCIINumeric {
+                result += "_"
+            }
+            if let firstNonNumericIndex = wordUTF8.firstIndex(where: { !$0._isASCIINumeric }),
+               wordUTF8[firstNonNumericIndex...].allSatisfy({ $0._isASCIIUppercase }) {
+                result += word
+            } else {
+                result += word.capitalized(with: nil)
+            }
+
+        }
+        return result
+    }
+}