A disease name is a conclusion. An observation is a fact. When a grower says "I have green mould", the adviser still asks: green where, on compost or casing, in one bag or twenty, since when? The name skipped every question that decides the action.
ICAR-DMR describes bacterial blotch by behaviour, not name: cap spots that enlarge when temperature is at least 20 °C and a film of water stays on the cap more than 3 hours. That tells you where to look, what to measure and what changed. Write the description before any name; if the name proves wrong, the description is still true.