A geocoder is a system that takes an address or other location and converts it into latitude and longitude coordinates. You might hide a letterbox in Lincoln Park, Seattle, WA, but Atlas Quest needs to know the exact coordinates of this park to make sure it shows up properly when people run a search for letterboxes near Seattle. For most cities, parks, and other points of interest, AQ will figure this out automatically using geocoders. Entering a location here will attempt to convert your human-friendly text into a location that computers can easily read and process.

When listing names of places, it's usually best to type in the full, official name of the park or location. Use a name such as "Montana de Oro State Park" instead of "Montana de Oro SP." Use the city name "San Francisco" instead of abbreviating it to "SF." The geocoders might be able to figure out your abbreviations, but they make fewer errors and better matches when you don't use them. It also helps when you include commas to separate each part of a location, so a search for "Milan, MI" may work better than a search for "Milan MI" (without the comma separating the state from the city.) Other punctuation is usually best if it's left out. (A search for "SW 23rd St" is more likely to generate better results than a search for "S.W. 23rd St.") Usually these little things won't matter, but in rare cases, they actually can make a difference!

One of several things might happen when you attempt to list a location:

• An exact match is found: This is ideal-it means the geocoder recognized what you typed and correctly figured out exactly what you were referring to.
• More than one match is found: This type of scenario might happen if you specify a location such as "Portland" as a location. There are 28 states that use "Portland" as a city name, and that doesn't even include cities outside of the United States such. England and Canada also have towns named Portland. AQ will display a list of the most likely candidates (you're almost certainly referring to the Portland in either Oregon or Maine since those are the two largest ones), and allow you to narrow down your choice. If the actual Portland you wanted isn't in the list, refine the location you searched for manually by adding a state or country as necessary.
• No exact matches are found: Sometimes you try a location and the geocoders aren't certain what you are referring to. This often happens if you misspell the name of a city or park, but it can also happen if the geocoder just doesn't know the location to which you refer at all. When this happens, AQ will display a list including possible matches due to misspellings as well as the 'closest' location it can find for your search. For instance, if you attempted a search for Lincln Park, Seattle, WA (notice that the O is missing from Lincoln), the geocoder won't find an exact match. But it might display a place called 'Lincoln Park' which seems to be pretty close, and it might also include an option for Seattle, WA. That last one may not be as accurate, but at least it puts your location in the correct city and that might be the best that the geocoder can do. You can also try adjusting what you typed for a location and try again.

Regardless of what happens, the last item in the list of possible matches will include a link to 'Edit Custom Location.' If it becomes clear that the suggested geocoded locations aren't what you're looking for, use this link to override the geocoder. Before clicking it, find the best match possible for your location-Atlas Quest will pre-populate the geocoder override with whatever match you select which can speed up the process. Click the best possible match from the list, then click the 'Edit Custom Location' link. (If you don't select a best possible match from the list, AQ will pre-populate the next page with the first location in the list.)