How do I mark touchers, including in the ditch?

A bowl in its original course that touches the jack is a toucher, even if it comes to rest in the ditch within the rink boundaries (law 14.1).

• On the green: you must mark all touchers with chalk, and remove chalk marks from non-touchers, as soon as they come to rest (law 42.2.10). A toucher can also be marked by a member of the team that delivered it (law 15.1).
• When marking would move the bowl: if the marker, or either player, thinks marking would likely move the bowl or alter the head, the bowl is not marked but nominated as a toucher instead (law 15.2). The same applies to removing a wrong mark: the bowl is nominated as a non-toucher (law 15.6).
• Time limit: if a bowl is neither marked nor nominated before the next bowl comes to rest (or, for the last bowl of an end, before the 30-second period under law 23.1), it is no longer a toucher (law 15.3).
• In the ditch: you must mark the position of a toucher, and of a live jack, with a brightly coloured indicator (white for the jack) not more than 50 mm wide and 100 mm high, placed vertically against the face of the bank or on top of it in line with the bowl. If the ditch surface is sand, lines can be drawn around it. If it is vegetation or synthetic, chalk lines can be drawn (laws 14.4, 18.2 and 42.2.13).
• Further movement: if a marked toucher or jack in the ditch is validly moved again, its new position must be marked by moving the indicators and redrawing the lines (laws 16.3 and 18.5).