Ridge count is the number of intervening ridges between a core and a delta on the impression of a loop or a whorl. If the exact count cannot be determined, minimum and maximum values can be specified; if it can, the count should be put in both the minimum and maximum fields. (See figure 1.)

The count begins at zero at the core and increases by one for each ridge crossed along a straight connecting line to the delta, not including ridges that form part of the core and the delta. If there are two cores or deltas, provide ridge counts between all cores and deltas, unless there are more than two cores or two deltas. In that case, only the leftmost and rightmost cores and deltas need to be used for ridge counts.

For whorls only, the following marking conventions shall be used:

• Because of the curving of ridges, the straight line between a core and a delta might cross a ridge twice (or more).
• Do not count the additional crossing unless the straight line first passes through at least the center of an adjacent valley.
• Do not count a ridge unless the straight line passes at least to the center of the ridge.

Core-delta ridge count is marked if EFS Profile 3: Detailed Markup Search Profile is to be used.

Count or estimate the number of ridges between the core and the delta. If you can determine the exact number, enter that number as the minimum and the maximum. If not, enter the range of possibilities.