:style() target, plain text with enough words to count.
Rule tier: action filters in the force tier. Rules test-adblock.com##.eng2306-style:style(opacity: 0 !important) and test-adblock.com##.eng2306-remove:remove() in an unflagged list. Our arm stages this rule through FilterManifestOverride (Adblock.ReleaseTests CosmeticTierFixturesTests); no shipped list has it. Brave turns a :style() on a plain selector into a stylesheet (cosmetic_filters_resources.cc:31-32) and runs :remove() as an action; Brave measures both as custom filters.
Expected in both modes: .eng2306-style hidden (opacity 0); .eng2306-remove removed from the DOM.
Expectations are Brave's verdicts, stated in pages/cosmetic-fixtures.json (ENG-2306); until Brave is measured they are hypotheses. The status line mirrors the Standard expectation.