But as an example, to get a latitude / longitude that can narrow a location down to a few feet you need 5 or 6 decimal digits or about 20 binary bits. So you need enough word salad in your email or ham radio message for the recipient to extract the 20 bits, decode it into a lat/long, punch it into their GPS and show up.
40 bits (20 bits for lat and 20 for long). Then throw in another 10 bits for date and hour of the day.