About RBD aka Ritual Biscuit Dunking,
On being handed ones mug of coffee, or, where staff shortages require one to make or collect it oneself, on attaining suitable braced position, gently test biscuit diameter across diameter of mug. The Very Best Biscuits will not fit into the mug. If the biscuit just reaches the surface of the coffee, allow it to soak for a few moments to attain preferred consistency under the local sludge factor which should be applied using the Mercator Spherical Projection Method. (If biscuit does nor reach surface, chew off short chord from edge and proceed as follows). On removi ng biscuit. gently chew off small dunked chord, leavi ng a short straight edge. Savour flavour and reapply sludge factor if necessary. Rotate biscuit so that straight edge is parallel with side of mug and dunk to a level of 3 - 4 millimetres for required time and remove. Chew off newly dunked segment, leavi ng two straight edges at right right angles. Savour for several seconds. Rotate biscuit so that shortest edge is presented to surface and dunk. Chew off small dunked segment and continue procedure until remaining segment is no longer large enough to dunk without wetting fingers. One is then faced with The Dunker's Dilemma: should one eat the remaining segment or drop it in the mug to be slurped later?
The very best authorities say that either course is acceptable but I prefer the former.