1 files changed, 43 insertions, 21 deletions
diff --git a/iredis/data/commands/geoadd.md b/iredis/data/commands/geoadd.md
index 32751db..65365bb 100644
--- a/iredis/data/commands/geoadd.md
+++ b/iredis/data/commands/geoadd.md
@@ -1,12 +1,13 @@
-Adds the specified geospatial items (latitude, longitude, name) to the specified
+Adds the specified geospatial items (longitude, latitude, name) to the specified
 key. Data is stored into the key as a sorted set, in a way that makes it
-possible to later retrieve items using a query by radius with the `GEORADIUS` or
-`GEORADIUSBYMEMBER` commands.
+possible to query the items with the `GEOSEARCH` command.
 
 The command takes arguments in the standard format x,y so the longitude must be
 specified before the latitude. There are limits to the coordinates that can be
-indexed: areas very near to the poles are not indexable. The exact limits, as
-specified by EPSG:900913 / EPSG:3785 / OSGEO:41001 are the following:
+indexed: areas very near to the poles are not indexable.
+
+The exact limits, as specified by EPSG:900913 / EPSG:3785 / OSGEO:41001 are the
+following:
 
 - Valid longitudes are from -180 to 180 degrees.
 - Valid latitudes are from -85.05112878 to 85.05112878 degrees.
@@ -14,37 +15,58 @@ specified by EPSG:900913 / EPSG:3785 / OSGEO:41001 are the following:
 The command will report an error when the user attempts to index coordinates
 outside the specified ranges.
 
-**Note:** there is no **GEODEL** command because you can use `ZREM` in order to
-remove elements. The Geo index structure is just a sorted set.
+**Note:** there is no **GEODEL** command because you can use `ZREM` to remove
+elements. The Geo index structure is just a sorted set.
+
+## GEOADD options
+
+`GEOADD` also provides the following options:
+
+- **XX**: Only update elements that already exist. Never add elements.
+- **NX**: Don't update already existing elements. Always add new elements.
+- **CH**: Modify the return value from the number of new elements added, to the
+  total number of elements changed (CH is an abbreviation of _changed_). Changed
+  elements are **new elements added** and elements already existing for which
+  **the coordinates was updated**. So elements specified in the command line
+  having the same score as they had in the past are not counted. Note: normally,
+  the return value of `GEOADD` only counts the number of new elements added.
+
+Note: The **XX** and **NX** options are mutually exclusive.
 
 ## How does it work?
 
 The way the sorted set is populated is using a technique called
 [Geohash](https://en.wikipedia.org/wiki/Geohash). Latitude and Longitude bits
-are interleaved in order to form an unique 52 bit integer. We know that a sorted
-set double score can represent a 52 bit integer without losing precision.
+are interleaved to form a unique 52-bit integer. We know that a sorted set
+double score can represent a 52-bit integer without losing precision.
 
-This format allows for radius querying by checking the 1+8 areas needed to cover
-the whole radius, and discarding elements outside the radius. The areas are
-checked by calculating the range of the box covered removing enough bits from
-the less significant part of the sorted set score, and computing the score range
-to query in the sorted set for each area.
+This format allows for bounding box and radius querying by checking the 1+8
+areas needed to cover the whole shape and discarding elements outside it. The
+areas are checked by calculating the range of the box covered, removing enough
+bits from the less significant part of the sorted set score, and computing the
+score range to query in the sorted set for each area.
 
 ## What Earth model does it use?
 
-It just assumes that the Earth is a sphere, since the used distance formula is
-the Haversine formula. This formula is only an approximation when applied to the
+The model assumes that the Earth is a sphere since it uses the Haversine formula
+to calculate distance. This formula is only an approximation when applied to the
 Earth, which is not a perfect sphere. The introduced errors are not an issue
-when used in the context of social network sites that need to query by radius
-and most other applications. However in the worst case the error may be up to
-0.5%, so you may want to consider other systems for error-critical applications.
+when used, for example, by social networks and similar applications requiring
+this type of querying. However, in the worst case, the error may be up to 0.5%,
+so you may want to consider other systems for error-critical applications.
 
 @return
 
 @integer-reply, specifically:
 
-- The number of elements added to the sorted set, not including elements already
-  existing for which the score was updated.
+- When used without optional arguments, the number of elements added to the
+  sorted set (excluding score updates).
+- If the `CH` option is specified, the number of elements that were changed
+  (added or updated).
+
+@history
+
+- `>= 6.2`: Added the `CH`, `NX` and `XX` options.
 
 @examples