Instead of emitting a CSS counter-reset for each footnote marker, Parsoid should emit literal text such as [3] or [٣], according to content language and custom group configuration. This is already how the legacy parser works.
Many sites are using CSS customizations for these numbers, and this must be considered during migration to explicit numbering. When this epic is complete, the customizations should be removed. The big relief here is that custom groups already need to be customized using all mechanisms, so we can rely on eg. the i18n message being available. Example custom group labels: fa:MediaWiki:Cite link label group-persian-alpha
Motivations:
- Makes it possible to do localization and alternative counter markers along with programmatic document rendering.
- Consolidate to a single mechanism.
- Plaintext compatibility (eg. copy and paste).
- Consistency in VE (TBD: explain in more detail)
- Prerequisite implement subreferencing
Historical notes:
- The legacy Cite parser has always used explicit numbering.
- CSS counter-reset numbering was first introduced into Parsoid in T86782: Use CSS to style Parsoid's Cite extension output to work around customization. At the time, Parsoid was written in JS and couldn't conveniently tap into the PHP i18n which provides custom numbering.
Out of scope: some related tasks will be implemented separately. Experience gained during this task can be applied to the other issues, we'll refine the other tasks' descriptions to add this info.