To give poeple a coordinates for location updates. Follow the letters in the column left to right. Then from the top mine in each column count down. Always state the column first, then row number.

ie - If you want to tell someone reinforce the center mine, simply say go to D,4.

A few tips from Antony's Guide:
(1) You can mine every 2 mins, each loss +1 min, each win -1 min
Loss -30 sec on mine cd, win-1min on mine cd

(2) Do not crowd mines, 100% output mine gives about 5k Drachmas, this is reduced by ½ if it’s overcrowded, and further if there’s more people, split out and max profit. Do not focus on the 2x mine since everyone will be there

(3) Max # of mines your faction controls, this increases the # people allowed per mine, so keep attacking!
There are also 4 abilities that pop up randomly, or when you reach your defensive quota:
(1) Harass - used on enemy mine to increase their mine time by 1 minute (affects all on a single mine?)
(2) "Horse Head" icon - instantly move to any mine our faction controls
(3) Incursion - attack a mine from anywhere (won't take but may drive def off)
(4) "Camp Fire" icon - one more that replenishes your troops, use it when timer is up

After the first 15 minutes have passed/no alliance forms?
An Alliance will automatically form if one faction's total holdings exceeds the combined holding of the two other factions. Deliberate with your faction to see if you can sustain fighting two factions at once.