{"success":true,"data":{"id":"subject-unicode-tag-chars","label":"Subject contains Unicode tag characters (U+E00xx) — ASCII smuggling / prompt injection","description":"The email subject line contains Unicode tag characters (U+E0020..U+E007F) — the same invisible-to-humans ASCII-smuggling codepoints detected in the body-level `body-unicode-tag-chars` signal, but sitting in the subject line instead. Subject-level smuggling is especially damaging because the subject flows directly into AI email classifiers as `Subject: ${...}`, into mobile notification previews, into inbox search indexes, and into mail rule predicates. Iter 431's `sanitizeAiInput` scrubs these before the Anthropic classifier prompt is built, but the user-facing scoring side was silent about subject-level tag chars until this iter. Detection fires on a single occurrence — legit email never carries even one. +5, decisive, parallel to the body-level sibling.","tier":"danger","category":"subject","isThin":false}}