News outlets write in recognizable ways, but how much of that style survives in a single headline once the topic is fixed, and what is it made of? We study outlet attribution from French news headlines under increasingly strict topic control, from category balancing to matched-event comparison. On an ACPM-anchored corpus of 170,160 headlines from ten national outlets across three hard-news categories, with outlets selected through external circulation/audience rankings, a fine-tuned CamemBERT identifies the publisher of an entity-masked headline in a future, unseen year at nearly six times chance; masking outlet self-references barely changes this. We then decompose the fingerprint within the interpretable character model (which alone is surface-strippable). Staged removal of surface form and named entities attributes it, in order-dependent shares, largely to presentation (casing, punctuation, typographic house style) and to a lexical residual that survives removing both, with a smaller share carried by which entities are named. An interpretable tone family adds almost nothing at the single-headline level, so the residual is not reducible to tone here. Category control alone cannot separate editorial form from an outlet’s story selection, so as a final check we hold the reported event constant, clustering same-event headlines across outlets and comparing them within cluster with a human-validated fixed-effects estimator. Both pre-specified attribution contrasts fall to near zero, while one validated difference survives: BFMTV foregrounds institutional and corporate actors as grammatical agents more than its peers. The result shows how much control is required before outlet differences can be read as framing rather than agenda. We release identifiers, hashes, code, derived features, the framing codebook, and gold annotations.