  * Add pattern tolerance option:
    + none
    + case
    + punctuation
    + names
    + versioning
    + hyphenation - add hyphenation pattern at each syllable (or suppress original hyphenation): (?:[-·]\s*)?
  * Add pattern scope option.
  * Add pattern keep option, like similar feature in Regexp::Common.
  * Add pattern keep-named option:
    + canonical - for the variation of a (sub)pattern preferred upstream
    + popular - skip obscure variations
  * Add pattern no-compile option, when compiling later e.g. with re::engine::RE2.
  * Cover license directories:
    + FSF: https://directory.fsf.org/wiki/Category:License
    + CC (retired): https://creativecommons.org/retiredlicenses/
    + GNU: https://www.gnu.org/licenses/license-list.html
    + Fedora: https://fedoraproject.org/wiki/Licensing#SoftwareLicenses
    + SUSE: https://github.com/openSUSE/spec-cleaner
    + Microsoft (non-free): https://en.wikipedia.org/wiki/Shared_source
    + Wikipedia: https://en.wikipedia.org/wiki/Category:Copyright_licenses
    + Debian (website): https://www.debian.org/legal/licenses/
    + Debian (wiki): https://wiki.debian.org/DFSGLicenses
    + W3C: https://www.w3.org/Consortium/Legal/2002/ipr-notice-20021231
    + http://www.linfo.org/main_index.html
  * Add author test checking validity of URLs.
    + Expand iri.alt.archive.FOO=BAR to https://web.archive.org/web/FOO/BAR
  * Add author test checking coverage of URL directories.
  * Cover comment styles (most possible):
    * https://en.wikipedia.org/wiki/Comparison_of_programming_languages_(syntax)#Comments
  * Cover RFN notice: https://wiki.debian.org/Fonts/Bugs/rfn-violation
  * Cover patent-related clauses:
    * http://en.swpat.org/wiki/Patent_clauses_in_software_licences
  * Cover a need of debian-policy to count popularity of licenses:
    * https://sources.debian.org/src/debian-policy/4.1.3.0/tools/license-count/?hl=63#L63
  * Maybe link (where appropriate) to kemitchell:
    * https://writing.kemitchell.com/
  * Cover P2P licensing:
    * https://wiki.p2pfoundation.net/P2P_Licensing
  * Locate and cover previous lesser-free licenses:
    * https://en.wikipedia.org/wiki/List_of_formerly_proprietary_software
  * Tag classifications:
    * https://en.wikipedia.org/wiki/Free_license#Classification_and_licenses
  * Improve testsuite:
    + Test static patterns directly (i.e. not using Regexp::Pattern::re)

Cover either grant or license for all objects, document as promise, and use both by default (not all patterns)

bail out if variants exists but no default (and simplify resolving)

test static patterns without using Regexp::Pattern::re

synthesize type:versioned iri from singleversion:$STEM as iri.alt.version.[/^$STEM_/]

speedup synthesizing by processing simplest first

Limit metadata name to shortnames usable in grant statements:
  * Move wikidata keys to new metadata field
  * Move elaborate wikipedia captions to summary
  * Synthesize tldr directly from caption

Improve grant synthesizing:
  * Expand to also cover lowercased names/captions
  * Expand to replace leading "Creative Commons" with "CC"
  * Expand to make leading "Creative Commons" (or "CC") optional
  * Reduce to skip duplicate names/captions (by mapping into a hash?)

Improve iri synthesizing:
  * Expand protocol https → http
  * Expand to alternate websites with same identifier

Relax tag "versioned" to any (even unknown) version

Fix join data from other licenses in code loop (not declared as a seed) e.g. for group gnu

Distinguish in testsuite between TODO (pending) and SKIP (irrelevant)

Assemble DefHash during build.
  * Maybe use Regexp::Assemble at build-time (but then optionally disable to support deterministic builds)
  * Install as YAML (and JSON?) below /usr/share/misc, for reuse by non-Perl tools.

Document new features:
  * Document subject option, including enabling multiple subjects.
  * Add note about "re" use...:
    adaptable by passing option C<subject> to L<Regexp::Pattern::re>.

Tighten what is public:
  * Join data from other licenses in code loop (not declared as a seed) e.g. for group gnu
  * Turn most possible into seed patterns.
