doc: Add documentation for Alphabet property

diff --git a/doc/messagemanager-api.txt b/doc/messagemanager-api.txt
index 0723e9c..848d6e3 100644 (file)
--- a/doc/messagemanager-api.txt
+++ b/doc/messagemanager-api.txt
@@ -86,3 +86,17 @@ Properties   string ServiceCenterAddress
                                "ps-preferred" - Use CS if PS is unavailable
 
                        By default oFono uses "cs-preferred" setting.
+
+               string Alphabet
+
+                       Contains the alphabet setting for outgoing SMSs.
+                       Possible values are:
+
+                               "default" - Default GSM alphabet
+                               "turkish" - Turkish alphabet
+                               "spanish" - Spanish alphabet
+                               "portuguese" - Portuguese alphabet
+
+                       The standard, language-specific alphabets are defined
+                       in 3GPP TS23.038, Annex A.  By default, oFono uses
+                       the "default" setting.