Link to existing highlight pseudo element spec: https://www.w3.org/TR/css-pseudo-4/#highlight-pseudos
Link to highlight API explainer: https://github.com/MicrosoftEdge/MSEdgeExplainers/blob/master/highlight/explainer.md

Short summary of the concept (first paragraph from highlight API explainer):
The Highlight API extends the concept of CSS 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, ::inactive-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, and spellchecking frameworks.

I would like to discuss this proposal with the CSS WG at TPAC 2019. Creating this issue to track that request.

Hoped outcomes from CSS WG discussion at TPAC:

• Familiarize CSS WG with the highlight API and take initial feedback
• Get approval to write an editor's draft and declare intent to publish a FPWD
• Discuss (and hopefully resolve) issues listed below

Issues to discuss:

• Status of implementer interest in existing highlight pseudo elements
• Relation between HighlightRange#priority and other highlight pseudo elements (Relation between HighlightRange#priority and other highlight pseudo elements MicrosoftEdge/MSEdgeExplainers#71)
• How should inline highlight range group styles with 'inherit' values be treated? (How should inline highlight range group styles with 'inherit' values be treated? MicrosoftEdge/MSEdgeExplainers#110)

Requested amount of time: 30 minutes