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`sylpheed-export export` reads `dat/GP_TITLE.pak`, enumerates its twelve screen builds, and writes each as one `sylpheed.screen/2` document with its sprite PNGs beside it. `sylpheed-export check` validates that tree against docs/FORMAT.md with no disc in hand — the P0 gate is "validates against FORMAT.md", which is not something anyone can confirm by reading, so it is a program. Two readings from FORMAT v1 turned out to be wrong and are corrected here rather than carried: * The focus sprite does NOT come from the element's `opt ` link. That was measured and refuted upstream, and this export shows why plainly: on the main menu `opt ` chains ptloop01 -> ptloop02 -> ptbtn01, two decorations and then a button. The highlight pairs by sprite NAME instead (ptbtn01.t32 <-> ptbtn01f.t32), which is the convention HANDOFF blesses and which resolves all five main-menu buttons. The raw link is still exported, renamed `opt_link` so nothing downstream mistakes it for navigation. * There are TWO modulate colours in different byte orders, and they multiply. v1's single `#rrggbbaa` could not carry both and silently dropped the alpha that every fade ramps. They are now `tint_rgba` and `fade_argb`, with the byte order in the key name, because getting it backwards is silent and reads as an art bug rather than a parse bug. The exporter takes exactly one authored input: `authored/screen_names.json`, because the disc does not name its builds and "build 5 is the main menu" is a measurement (HANDOFF Q2), not a field. Every name it applies is stamped `name_source: "authored"` with the evidence in `name_why`, and `check` rejects an authored name that has no `why` — so the derived tree stays honest about which of its fields is a decision. Sprites are per screen, not a flat pool: `main_menu` and `extras` both ship a `ptbase.t32` and they are different pictures. Checked, not assumed: * two exports of the same disc are byte-identical; * five mutations of a valid main_menu.json — a broken paint_order permutation, a dangling focus_sprite, a reversed buttons list, a `#rrggbbaa` colour and an invented name_source — are each caught with a specific message. `t` stays raw. Q1 is answered, but the seconds conversion is measured off the running game and its own finding flags the frame-rate measurement as the part worth re-testing; if the game presents at 60 Hz every duration halves. One constant, at P2, in a file that says it is a decision.