2 SPDX-FileCopyrightText: 2024 Lady <https://www.ladys.computer/about/#lady>
 
   3 SPDX-License-Identifier: CC0-1.0
 
   7 <b>A make·file for X·M·L.</b>
 
   9 <dfn>⛩️📰 书社</dfn> aims to make it easy to generate websites with
 
  10   X·S·L·T and G·N·U Make.
 
  11 It is consequently only a good choice for people who like X·S·L·T and
 
  12   G·N·U Make and wish it were easier to make websites with them.
 
  14 It makes things easier by :—
 
  16 - Automatically identifying source files and characterizing them by
 
  17     type (X·M·L, text, or asset).
 
  19 - Parsing supported text types into X·M·L trees.
 
  21 - Enabling easy inclusion of source files within each other.
 
  23 It aims to do this with zero dependencies beyond the programs already
 
  24   installed on your computer†.
 
  26 † Assuming an operating system with a fairly featureful, and
 
  27   Posix‐compliant, development setup (e·g, macOS).
 
  28 In fact, on Linux you will probably need to install a few programs:
 
  29   `libxml2-utils`, `xsltproc`, `sharutils`, and `pax`.
 
  33 <i lang="cmn-Hans">书社</i> is a Chinese word meaning “publishing
 
  36 The first character, <i lang="cmn-Hans">书</i>, is the simplified form
 
  39 The second character, <i lang="cmn-Hans">社</i>, contemporarily means
 
  40   “association”, but historically referred to the god of the soil and
 
  41   related altars or festivities.
 
  42 In Japanese, it is an alternate spelling for <i lang="ja">やしろ</i>,
 
  43   the word for “Shinto shrine”.
 
  45 The name <i lang="cmn-Hans">书社</i> was chosen to play on this pun, as
 
  46   it is intended as a publishing program for webshrines.
 
  48 In Ascii environments, ⛩️📰 书社 should be written `Shushe`, following
 
  49   the pinyin transliteration.
 
  53 In most cases, ⛩️📰 书社 aims to require only functionality which is
 
  54   present in all Posix‐compliant operating systems.
 
  55 There are a few exceptions.
 
  56 Details on particular programs are given below; if a program is not
 
  57   listed, it is assumed that any Posix‐compliant implementation will
 
  62 This is a Posix utility, but ⛩️📰 书社 currently depends on
 
  63   unspecified behaviour.
 
  64 When the G·N·U version of `stat` is being used, then the G·N·U version
 
  65   of `date` is also expected.
 
  69 This is a Posix utility, but ⛩️📰 书社 currently depends on
 
  70   unspecified behaviour.
 
  71 It requires support for the following additional options :—
 
  73 - **`-C`**, when supplied with `-m`, must be useable to compile a
 
  74     `.mgc` magicfile for use with future invocations of `file`.
 
  76 - **`--files-from`** must be useable to provide a file that `file`
 
  77     should read file·names from, and `-` must be useable in this
 
  78     context to specify the standard input.
 
  80 - **`--mime-type`** must cause `file` to print the internet media type
 
  81     of the file with no charset parameter.
 
  83 - **`--separator`** must be useable to set the separator that `file`
 
  84     uses to separate file names from types.
 
  86 These options are implemented by the
 
  87   [Fine Free File Command](https://darwinsys.com/file/), which is used
 
  88   by most operating systems.
 
  92 This is not a Posix utility.
 
  93 Usage of `git` is optional, but recommended (and activated by default).
 
  94 To disable it, set `GIT=`.
 
  98 This is a Posix utility, but ⛩️📰 书社 currently depends on
 
  99   unspecified behaviour.
 
 100 ⛩️📰 书社 requires specifically the G·N·U version of `make`, and
 
 101   depends on functionality present in version 3.81 or later.
 
 102 It is not expected to work in previous versions, or with other
 
 103   implementations of Make.
 
 107 This is a Posix utility, but not included in the Linux Standard Base or
 
 108   installed by default in many distributions.
 
 109 Only `ustar` format support is required.
 
 113 This is not a Posix utility, and nor is it particularly portable.
 
 114 To get around incompatibilities, ⛩️📰 书社 attempts to recognize G·N·U
 
 115   `stat` by searching for the string `GNU` when invoked with the
 
 116   `--version` option, and falls back to B·S·D behaviour otherwise.
 
 118 ### `uudecode` and `uuencode`
 
 120 These are Posix utilities, but not included in the Linux Standard Base
 
 121   or installed by default in many distributions.
 
 122 The G·N·U [Sharutils](https://www.gnu.org/software/sharutils/) package
 
 123   can be installed to access them.
 
 127 This is a Posix utility, but ⛩️📰 书社 currently depends on
 
 128   unspecified behaviour.
 
 129 It requires support for the `-0` flag, which must disable the special
 
 130   quote and whitespace handling of `xargs` in favour of null‐terminated
 
 133 ### `xmlcatalog` and `xmllint`
 
 135 These are not a Posix utilities.
 
 136 They is a part of `libxml2`, but may need to be installed separately
 
 137   (e·g by the name `libxml2-utils`).
 
 141 This is not a Posix utility.
 
 142 It is a part of `libxslt`, but may need to be installed separately.
 
 146 Place source files in `sources/` and run `make install` to compile
 
 147   the result to `public/`.
 
 148 Compilation involves the following steps :—
 
 150 1. ⛩️📰 书社 compiles all of the magic files in `magic/` into a single
 
 151     file, `build/magic.mgc`.
 
 153 2. ⛩️📰 书社 processes all of the parsers in `parsers/` and determines
 
 154     the list of supported plaintext types.
 
 156 3. ⛩️📰 书社 identifies all of the source files and includes and uses
 
 157     `build/magic.mgc` to classify them by media type.
 
 159 4. ⛩️📰 书社 parses all plaintext and X·M·L source files and includes
 
 160     and then builds a dependency tree between them.
 
 162 5. ⛩️📰 书社 uses the dependency tree to establish prerequisites for
 
 165 6. ⛩️📰 书社 compiles each output file to `build/result`.
 
 167 7. ⛩️📰 书社 copies most output files from `build/result` to
 
 168      `build/public`, but it does some additional processing instead on
 
 169      those which indicate a non‐X·M·L desired final output form.
 
 171 8. ⛩️📰 书社 copies the final resulting files to `public`.
 
 173 You can use `make list` to list each identified source file or include
 
 174   alongside its computed type and dependencies.
 
 175 As this is a Make‐based program, steps will only be run if the
 
 176   corresponding buildfile or output file is older than its
 
 181 The ⛩️📰 书社 name·space is `urn:fdc:ladys.computer:20231231:Shu1She4`.
 
 183 This document uses a few name·space prefixes, with the following
 
 186 |     Prefix | Expansion                                     |
 
 187 | ---------: | :-------------------------------------------- |
 
 188 | `catalog:` | `urn:oasis:names:tc:entity:xmlns:xml:catalog` |
 
 189 |    `exsl:` | `http://exslt.org/common`                     |
 
 190 | `exslstr:` | `http://exslt.org/strings`                    |
 
 191 |    `html:` | `http://www.w3.org/1999/xhtml`                |
 
 192 |     `svg:` | `http://www.w3.org/2000/svg`                  |
 
 193 |   `xlink:` | `http://www.w3.org/1999/xlink`                |
 
 194 |    `xslt:` | `http://www.w3.org/1999/XSL/Transform`        |
 
 195 |    `书社:` | `urn:fdc:ladys.computer:20231231:Shu1She4`    |
 
 197 ## Setup and Configuration
 
 199 ⛩️📰 书社 depends on the following programs to run.
 
 200 In every case, you may supply your own implementation by overriding the
 
 201   corresponding (allcaps) variable (e·g, set `MKDIR` to supply your own
 
 202   `mkdir` implementation).
 
 212 - `git` (optional; set `GIT=` to disable)
 
 219 - `pax` (only when generating archives)
 
 224 - `stat` (BSD *or* GNU)
 
 230 - `xargs` (requires support for `-0`)
 
 231 - `xmlcatalog` (provided by `libxml2`)
 
 232 - `xmllint` (provided by `libxml2`)
 
 233 - `xsltproc` (provided by `libxslt`)
 
 235 The following additional variables can be used to control the behaviour
 
 239   The location of the source files (default: `sources`).
 
 240   Multiple source directories can be provided, so long as the same
 
 241     file subpath doesn’t exist in more than one of them.
 
 244   The location of source includes (default: `sources/includes`).
 
 245   This can be inside of `SRCDIR`, but needn’t be.
 
 246   Multiple include directories can be provided, so long as the same
 
 247     file subpath doesn’t exist in more than one of them.
 
 250   The location of the (temporary) build directory (default: `build`).
 
 251   `make clean` will delete this, and it is recommended that it not be
 
 252     used for programs aside from ⛩️📰 书社.
 
 255   The location of directory to output files to (default: `public`).
 
 256   `make install` will overwrite files in this directory which
 
 257     correspond to those in `SRCDIR`.
 
 258   It *will not* touch other files, including those generated from files
 
 259     in `SRCDIR` which have since been deleted.
 
 261   Files are first compiled to `$(BUILDDIR)/public` before they are
 
 262     copied to `DESTDIR`, so this folder is relatively quick and
 
 263     inexpensive to re·create.
 
 264   It’s reasonable to simply delete it before every `make install` to
 
 265     ensure stale content is removed.
 
 268   The location of the ⛩️📰 书社 `GNUmakefile`.
 
 269   This should be set automatically when calling Make and shouldn’t ever
 
 270     need to be set manually.
 
 271   This variable is used to find the ⛩️📰 书社 `lib/` folder, which is
 
 272     expected to be in the same location.
 
 275   A white·space‐separated list of magic files to use (default:
 
 276     `$(THISDIR)/magic/*`).
 
 279   The value of this variable is appended to `MAGIC` by default, to
 
 280     enable additional magic files without overriding the existing ones.
 
 283   Rules to use with `find` when searching for source files.
 
 284   The default ignores files that start with a period or hyphen‐minus,
 
 285     those which end with a cloparen, and those which contain a hash,
 
 286     buck, percent, asterisk, colon, semi, eroteme, bracket, backslash,
 
 289 - **`EXTRAFINDRULES`:**
 
 290   The value of this variable is appended to `FINDRULES` by default, to
 
 291     enable additional rules without overriding the existing ones.
 
 293 - **`FINDINCLUDERULES`:**
 
 294   Rules to use with `find` when searching for includes (default:
 
 297 - **`EXTRAFINDINCLUDERULES`:**
 
 298   The value of this variable is appended to `FINDINCLUDERULES` by
 
 299     default, to enable additional rules without overriding the existing
 
 303   A white·space‐separated list of parsers to use (default:
 
 304     `$(THISDIR)/parsers/*.xslt`).
 
 306 - **`EXTRAPARSERS`:**
 
 307   The value of this variable is appended to `PARSERS` by default, to
 
 308     enable additional parsers without overriding the existing ones.
 
 311   A white·space‐separated list of transforms to use (default:
 
 312     `$(THISDIR)/transforms/*.xslt`).
 
 314 - **`EXTRATRANSFORMS`:**
 
 315   The value of this variable is appended to `TRANSFORMS` by default, to
 
 316     enable additional transforms without overriding the existing ones.
 
 319   A white·space‐separated list of media types to consider X·M·L
 
 320     (default: `application/xml text/xml`).
 
 323   The current version of ⛩️📰 书社 (default: derived from the current
 
 324     git tag/branch/commit).
 
 327   The current version of the source files (default: derived from the
 
 328     current git tag/branch/commit).
 
 331   If this variable has a value, every recipe instruction will be
 
 332     printed when it runs (default: empty).
 
 333   This is helpful for debugging, but typically too noisy for general
 
 338 Source files may be placed in `SRCDIR` in any manner; the file
 
 339   structure used there will match the output.
 
 340 The type of source files is *not* determined by file extension, but
 
 341   rather by magic number; this means that files **must** begin with
 
 342   something recognizable.
 
 343 Supported magic numbers include :—
 
 345 - `<?xml` for `application/xml` files
 
 346 - `#!js` for `text/javascript` files
 
 347 - `@charset "` for `text/css` files
 
 348 - `#!tsv` for `text/tab-separated-values` files
 
 349 - `%%` for `text/record-jar` files (unregistered; see
 
 350     [[draft-phillips-record-jar-01][]])
 
 352 Text formats with associated X·S·L·T parsers are wrapped in a H·T·M·L
 
 353   `<script>` element whose `@type` gives its media type, and then
 
 354   passed to the parser to process.
 
 355 Source files whose media type does not have an associated X·S·L·T
 
 356   parser are considered “assets” and will not be transformed.
 
 358 **☡ For compatibility with this program, source file·names must not
 
 359   contain Ascii white·space, colons (`:`), semis (`;`), pipes (`|`),
 
 360   bucks (`$`), percents (`%`), hashes (`#`), asterisks (`*`), brackets
 
 361   (`[` or `]`), erotemes (`?`), backslashes (`\`), or control
 
 362   characters, must not begin with a hyphen‐minus (`-`), must not end
 
 363   with a cloparen (`)`), and must not contain quoted braces (`"{` or
 
 365 The former characters have the potential to conflict with make syntax,
 
 366   a leading hyphen‐minus is confusable for a command‐line argument, a
 
 367   trailing cloparen [activates a bug in G·N·U Make
 
 368   3.81](https://stackoverflow.com/questions/17148468/capturing-filenames-including-parentheses-with-gnu-makes-wildcard-function#comment24825307_17148894),
 
 369   and quoted braces are used internally by the program.
 
 373 Parsers are used to convert plaintext files into X·M·L trees, as well
 
 374   as convert plaintext formats which are already included inline in
 
 375   existing source X·M·L documents.
 
 376 ⛩️📰 书社 comes with some parsers; namely :—
 
 378 - **`parsers/plain.xslt`:**
 
 379   Wraps `text/plain` contents in a `<html:pre>` element.
 
 381 - **`parsers/record-jar.xslt`:**
 
 382   Converts `text/record-jar` contents into a `<html:div>` of
 
 383     `<html:dl>` elements (one for each record).
 
 385 - **`parsers/tsv.xslt`:**
 
 386   Converts `text/tab-separated-values` contents into an `<html:table>`
 
 389 New ⛩️📰 书社 parsers which target plaintext formats should have an
 
 390   `<xslt:template>` element with no `@name` or `@mode` and whose
 
 393 - Starts with an appropriately‐name·spaced qualified name for a
 
 394     `<html:script>` element.
 
 396 - Follows this with the string `[@type=`.
 
 398 - Follows this with a quoted string giving a media type supported by
 
 400   Media type parameters are *not* supported.
 
 402 - Follows this with the string `]`.
 
 404 For example, the trivial `text/plain` parser is defined as follows :—
 
 407 <?xml version="1.0"?>
 
 409   xmlns="http://www.w3.org/1999/XSL/Transform"
 
 410   xmlns:html="http://www.w3.org/1999/xhtml"
 
 411   xmlns:书社="urn:fdc:ladys.computer:20231231:Shu1She4"
 
 414   <书社:id>example:text/plain</书社:id>
 
 415   <template match="html:script[@type='text/plain']">
 
 416     <html:pre><value-of select="."/></html:pre>
 
 421 ⛩️📰 书社 will scan the provided parsers for this pattern to determine
 
 422   the set of allowed plaintext file types.
 
 423 Multiple such `<xslt:template>` elements may be provided in a single
 
 424   parser, for example if the parser supports multiple media types.
 
 425 Alternatively, you can set the `@书社:supported-media-types` attribute
 
 426   on the root element of the parser to override media type support
 
 429 Even when `@书社:supported-media-types` is set, it is a requirement
 
 430   that each parser transform any `<html:script>` elements with a
 
 431   `@type` which matches their registered types into something else.
 
 432 Otherwise the parser will be stuck in an endless loop.
 
 433 The result tree of applying the transform to the `<html:script>`
 
 434   element will be reparsed (in case any new `<html:script>` elements
 
 435   were added in its subtree), and a `@书社:parsed-by` attribute will be
 
 436   added to each toplevel element in the result.
 
 437 The value of this attribute will be the value of the `<书社:id>`
 
 438   toplevel element in the parser.
 
 440 It is possible for parsers to support zero plaintext types.
 
 441 This is useful when targeting specific dialects of X·M·L; parsers in
 
 442   this sense operate on the same basic principles as transforms
 
 444 The major distinction between X·M·L parsers and transforms is where in
 
 445   the process the transformation happens:
 
 446 Parsers are applied *prior* to embedding (and can be used to generate
 
 447   embeds); transforms are applied *after*.
 
 449 It is **strongly recommended** that auxillary templates in parsers be
 
 450   name·spaced (by `@name` or `@mode`) whenever possible, to avoid
 
 451   conflicts between parsers.
 
 453 ### Attributes added during parsing
 
 455 ⛩️📰 书社 will add a few attributes to the output of the parsing step,
 
 458 - A `@书社:cksum` attribute on toplevel result elements, giving the
 
 459     `cksum` checksum of the corresponding source file.
 
 461 - For the elements which result from parsing plaintext `<html:script>`
 
 464   - A `@书社:parsed-by` attribute, giving a space‐separated list of
 
 465       parsers which parsed the node.
 
 466     (Generally, this will be a list of one, but it is possible for the
 
 467       result of a parse to be another plaintext node, which may be
 
 468       parsed by a different parser.)
 
 470   - A `@书社:media-type` attribute, giving the identified media type of
 
 475 Documents can be embedded in other documents using a `<书社:link>`
 
 476   element with `@xlink:show="embed"`.
 
 477 The `@xlink:href`s of these elements should have the format
 
 478   `about:shushe?source=<path>`, where `<path>` provides the path to the
 
 479   file within `SRCDIR`.
 
 480 Includes, which do not generate outputs of their own but may still be
 
 481   freely embedded, instead use the format
 
 482   `about:shushe?include=<path>`, where `<path>` provides the path
 
 485 Embeds are replaced with the parsed contents of a file, unless the file
 
 486   is an asset, in which case an `<html:object>` element is produced
 
 487   instead (with the contents of the asset file provided as a base64
 
 489 Embed replacements will be given a `@书社:identifier` attribute whose
 
 490   value will match the `@xlink:href` of the embed.
 
 492 Embedding takes place after parsing but before transformation, so
 
 493   parsers are able to generate their own embeds.
 
 494 ⛩️📰 书社 is able to detect the transitive embed dependencies of files
 
 495   and update them accordingly; it will signal an error if the
 
 496   dependencies are recursive.
 
 498 ## Output Redirection
 
 500 By default, ⛩️📰 书社 installs files to the same location in `DESTDIR`
 
 501   as they were placed in their `SRCDIR`.
 
 502 This behaviour can be customized by setting the `@书社:destination`
 
 503   attribute on the root element, whose value can give a different path.
 
 504 This attribute is read after parsing, but before transformation (where
 
 505   it is silently dropped).
 
 509 Transforms are used to convert X·M·L files into their final output,
 
 510   after all necessary parsing and embedding has taken place.
 
 511 ⛩️📰 书社 comes with some transforms; namely :—
 
 513 - **`transforms/asset.xslt`:**
 
 514   Converts `<html:object>` elements which correspond to recognized
 
 515     media types into the appropriate H·T·M·L elements, and deletes
 
 516     `<html:style>` elements from the body of the document and moves
 
 519 - **`transforms/metadata.xslt`:**
 
 520   Provides basic `<html:head>` metadata.
 
 521   This metadata is generated from `<html:meta>` elements with one of
 
 522     the following `@itemprop` attributes :—
 
 524   - **`urn:fdc:ladys.computer:20231231:Shu1She4:title`:**
 
 525     Provides the title of the page.
 
 527   ⛩️📰 书社 automatically encapsulates H·T·M·L embeds so that their
 
 528     metadata does not propogate up to the embedding document.
 
 529   To undo this behaviour, remove the `@itemscope` and `@itemtype`
 
 530     attributes from the embed during the transformation phase.
 
 532 - **`transforms/serialization.xslt`:**
 
 533   Replaces `<书社:serialize-xml>` elements with the (escaped)
 
 534     serialized X·M·L of their contents.
 
 535   This replacement happens during the application phase, after most
 
 536     other transformations have taken place.
 
 538   If a `@with-namespaces` attribute is provided, any name·space nodes
 
 539     on the toplevel serialized elements whose U·R·I’s correspond to the
 
 540     definitions of the provided prefixes, as defined for the
 
 541     `<书社:serialize-xml>` element, will be declared using name·space
 
 542     attributes on the serialized elements.
 
 543   Otherwise, only name·space nodes which _differ_ from the definitions
 
 544     on the `<书社:serialize-xml>` element will be declared.
 
 545   The string `#default` may be used to represent the default
 
 547   Multiple prefixes may be provided, separated by white·space.
 
 549   When it comes to name·spaces used internally by ⛩️📰 书社, the
 
 550     prefix used by ⛩️📰 书社 may be declared _in addition to_ the
 
 551     prefix(es) used in the source document(s).
 
 552   It is not possible to selectively only declare one prefix for a
 
 553     name·space to the exclusion of others.
 
 555   `<书社:raw-output>` elements may be used inside of
 
 556     `<书社:serialize-xml>` elements to inject raw output into the
 
 559 The following are recommendations on effective creation of
 
 562 - Make template matchers as specific as possible.
 
 563   It is likely an error if two transforms have templates which match
 
 564     the same element (unless the templates have different priority).
 
 566 - Name·space templates (with `@name` or `@mode`) whenever possible.
 
 568 - Set `@exclude-result-prefixes` on the root `xslt:transform` element
 
 569     to reduce the number of declared name·spaces in the final result.
 
 573 The following params are made available globally in parsers and
 
 580   The checksum of the source file (⅌ `cksum`).
 
 583   The ⛩️📰 书社 identifier of the source file (a u·r·i beginning with
 
 587   The value of the `SRCREV` variable (if present).
 
 590   The time at which the source file was last modified.
 
 593   The value of the `THISREV` variable (if present).
 
 595 The following params are only available in transforms :—
 
 598   The path of the catalog file (within `BUILDDIR`).
 
 601   The path of the output file (within `DESTDIR`).
 
 605 ⛩️📰 书社 will wrap the final output of the transforms in appropriate
 
 606   `<html:html>` and `<html:body>` elements, so it is not necessary for
 
 607   transforms to do this explicitly.
 
 608 After performing the initial transform, ⛩️📰 书社 will match the root
 
 609   node of the result in the following modes to fill in areas of the
 
 613   The result of matching in this mode is prepended into the
 
 614     `<html:body>` of the output (before the transformation result).
 
 617   The result of matching in this mode is appended into the
 
 618     `<html:body>` of the output (after the transformation result).
 
 621   The result of matching in this mode is inserted into the
 
 622     `<html:head>` of the output.
 
 624 In addition to being called with the transform result, each of these
 
 625   modes will additionally be called with a `<xslt:include>` element
 
 626   corresponding to each transform.
 
 627 If a transform has a `<书社:id>` top‐level element whose value is an
 
 628   i·r·i, its `<xslt:include>` element will have a corresponding
 
 630 This mechanism can be used to allow transforms to insert content
 
 631   without matching any elements in the result; for example, the
 
 632   following transform adds a link to a stylesheet to the `<html:head>`
 
 636 <?xml version="1.0"?>
 
 638   xmlns="http://www.w3.org/1999/XSL/Transform"
 
 639   xmlns:html="http://www.w3.org/1999/xhtml"
 
 640   xmlns:xslt="http://www.w3.org/1999/XSL/Transform"
 
 641   xmlns:书社="urn:fdc:ladys.computer:20231231:Shu1She4"
 
 642   exclude-result-prefixes="书社"
 
 645   <书社:id>example:add-stylesheet-links.xslt</书社:id>
 
 646   <template match="xslt:include[@书社:id='example:add-stylesheet-links.xslt']" mode="书社:metadata">
 
 647     <html:link rel="stylesheet" type="text/css" href="/style.css"/>
 
 652 Output wrapping can be entirely disabled by adding a
 
 653   `@书社:disable-output-wrapping` attribute to the top‐level element in
 
 655 It will not be performed on outputs whose root elements are
 
 656   `<书社:archive>`, `<书社:base64-binary>`, or `<书社:raw-text>`
 
 659 ## Applying Attributes
 
 661 The `<书社:apply-attributes>` element will apply any attributes on the
 
 662   element to the element(s) it wraps.
 
 663 It is especially useful in combination with embeds.
 
 665 The `<书社:apply-attributes-to-root>` element will apply any attributes
 
 666   on the element to the root node of the final transformation result.
 
 667 It is especially useful in combination with output wrapping.
 
 669 In both cases, attributes from various sources are combined with
 
 670   white·space between them.
 
 671 Attribute application takes place after all ordinary transforms have
 
 674 Both elements ignore attributes in the `xml:` name·space, except for
 
 675   `@xml:lang`, which ignores all but the first definition (including
 
 676   any already present on the root element).
 
 677 On H·T·M·L and S·V·G elements, `@lang` has the same behaviour as
 
 680 ## Other Kinds of Output
 
 682 There are a few special elements in the `书社:` name·space which, if
 
 683   they appear as the toplevel element in a transformation result, cause
 
 684   ⛩️📰 书社 to produce something other than an X·M·L file.
 
 687 - **`<书社:archive>`:**
 
 688   Each child element with a `@书社:archived-as` attribute will be
 
 689     archived as a separate file in a resulting tarball (this attribute
 
 690     gives the file name).
 
 691   These elements will be processed the same as the root elements of any
 
 692     other file (e·g, they will be wrapped; they can themselves specify
 
 693     non X·M·L output types, ⁊·c).
 
 694   Other child elements will be ignored.
 
 696 - **`<书社:base64-binary>`:**
 
 697   The text nodes in the transformation result will, after removing all
 
 698     Ascii whitespace, be treated as a Base·64 string, which is then
 
 701 - **`<书社:raw-text>`:**
 
 702   A plaintext (U·T·F‐8) file will be produced from the text nodes in
 
 703     the transformation result.
 
 707 It is possible to have a single source file produce multiple output
 
 708   files via `<书社:page>` elements, whose `@name` gives the name of the
 
 710 If a parsed document has a `@书社:destination` which contains `%s`,
 
 711   the `%s` will be replaced with the `@name` for each `<书社:page>` (and
 
 712   removed for the main output).
 
 713 Otherwise, the `@name` is inserted before the first period of the
 
 714   filename (or at the end of the filename for those with no period).
 
 715 If `<书社:page>`s do not have a `@name`, they are numbered
 
 717 The destination of pages must be in the same directory as their parent.
 
 719 Pagination essentially forms a limited convenience for the more
 
 720   sophisticated technique of creating an archive with ⛩️📰 书社 and
 
 722 Pages are, from Make’s point of view, untracked side·effects of
 
 723   installing the main output, meaning they cannot be targeted directly
 
 724   and will not appear in `make list` or `make listout`.
 
 725 They are intended solely for the like of indices and feeds, for which
 
 726   convenience and necessity outweigh their flaws.
 
 730 This repository conforms to [REUSE][].
 
 732 Most source files are licensed under the terms of the <cite>Mozilla
 
 733   Public License, version 2.0</cite>.
 
 735 [REUSE]: <https://reuse.software/spec/>
 
 736 [draft-phillips-record-jar-01]: <https://datatracker.ietf.org/doc/html/draft-phillips-record-jar-01>