Just a simple 2 stage multi that may fill a hole on your grid or a day you may need.
At the posted coordinates you will find a marker with a phone number on it.
ABC DEF-GHIJ
Use the formula below to find the coordinates of the final
Assume N 41 and W 90
N (E-F) (I+J). (A-D) (H-E) (H+F)
W (F-J) (H+F), (E+I) (D-H) (H+I)