Asked for by the user (messages 154 and 165 on main, 2026-09-18): "plan titles can only be so long, so we have to set a character limit. Work titles can also only be so long. If you want to elaborate on work, you have to add a brief, not an insanely long title. A good title is 'The plan page restyled after users' mockup.' If a plan or a work title contains a colon, meaning you are explaining something, that should not be allowed. Tell it: hard deny on detection. To-do title: same thing. All research titles, actually."

Enforced in titles.check(), called by plans.add and plans.edit, work.start, todo.add and todo.retitle, reports.add: past 80 characters, or with a colon, the write is refused with the reason. Rows written before the rule keep their titles. What was rule 12 (two to five words) is folded into this one: the measure is the limit and the colon, not a word count.