你好 TAG! 吃饭了吗？

I'm requesting a TAG review of CSS Custom Highlight API Module Level 1, which was recently published as a FPWD.

The Custom Highlight API extends the concept of highlight pseudo-elements (see CSS Pseudo-Elements 4 §3 Highlight Pseudo-elements) by providing a way for web developers to style the text of arbitrary Range objects, rather than being limited to the user agent defined ::selection, ::spelling-error, and ::grammar-error. This is useful in a variety of scenarios, including editing frameworks that wish to implement their own selection, find-on-page over virtualized documents, multiple selection to represent online collaboration, or spellchecking frameworks. The Custom Highlight API provides a programmatic way of adding and removing highlights that do not affect the underlying DOM structure, but instead applies styles to text based on range objects, accessed via the ::highlight() pseudo element.

• Explainer¹ (minimally containing user needs and example code): https://github.com/MicrosoftEdge/MSEdgeExplainers/blob/main/highlight/explainer.md (largely superseded by the spec's own intro section, but may still be of interest for discussions of alternatives)
• Specification URL: https://www.w3.org/TR/css-highlight-api-1/
• Tests: none yet :(
• Security and Privacy self-review²: https://lists.w3.org/Archives/Public/www-style/2020Dec/0007.html
• GitHub repo (if you prefer feedback filed there): https://github.com/w3c/csswg-drafts (one issue per comment please)
• Primary contacts (and their relationship to the specification):
  • Florian Rivoal (@frivoal), Invited Expert, co-editor
  • Sanket Joshi (@sanketj), Microsoft, co-editor
  • Megan Gardner, Apple, co-editor
  • Rossen Atanassof, @atanassov, Microsoft, co-chair
  • Alan Stearns @astearns, Adobe, co-chair
• Organization(s)/project(s) driving the specification: CSSWG
• Key pieces of existing multi-stakeholder review or discussion of this specification:
  • https://github.com/MicrosoftEdge/MSEdgeExplainers/issues?q=label%3A%22Highlight+API%22+
  • https://github.com/w3c/csswg-drafts/issues?q=is%3Aissue+label%3Acss-highlight-api-1+
• External status/issue trackers for this specification (publicly visible, e.g. Chrome Status):
  • Implemented in Safari since release preview 99

Further details:

• I have reviewed the TAG's API Design Principles
• Relevant time constraints or deadlines: Nothing in particular
• The group where the work on this specification is currently being done: CSSWG
• The group where standardization of this work is intended to be done (if current group is a community group or other incubation venue): CSSWG
• Major unresolved issues with or opposition to this specification: No known opposition, event part still missing
• This work is being funded by: Bloomberg, Microsoft, Apple

We'd prefer the TAG provide feedback as 🐛 open issues in our GitHub repo for each point of feedback