And% books the resource for a given percentage of the prime resource from the start of the prime to the end of the prime.  In the example below, And% 25 would book 25% of the time used on the prime resource on the second resource from the start date of the prime to the end date of the prime.  If the percentage calculation is greater than the capacity of the resource, the maximum amount of the resource is used. For example, if the prime resource was booked for 8 hours per day and a And% 25 command was given, the second resource would be booked for 2 hours per day (8 hours of the prime resource X 25% = 2 hours).

You cannot have a And% command that is variable.  The scheduler will reset the command to be And and treat it as a And Variable.

In the example below, operation 15 is scheduled on the CNC 4 Axis-1 with a CNC Labor resource required 25% of the time: